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How to identify the highest and lowest pixels within a defined neighborhood area of a central pixel

FidelTedla

Hi,

I am using the 'range' statistics type within the 'focal statistics' tool. For each central pixel ArcGIS calculates the difference between the highest and lowest values in the defined neighborhood area and assigns it to the central pixel. What I am now looking for is a way to identify the highest and lowest pixels within that defined neighborhood area.

Any help is much appreciated.

Regards,

Fidel

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DanPatterson_Retired

focal statistics minimum and focal statistics max plus all the other tools in the focal statistics tools in ArcToolbox will cover all combinations and permutations of gleaning other information

FidelTedla

Hi Dan,

Thanks for the reply.

Yes, but what I am trying to find out is to actually locate the max and min pixels. The focal statistics tools assign the results of the operation to the central pixel and do not give the actual location of the max/min pixels as an output.

Regards,

Fidel

XanderBakker

You can use Focal Flow—Help | ArcGIS Desktop to determine the location of the lowest value. To determine the maximum value, invert your raster (highest value - original raster) and run again.

DanPatterson_Retired

so if you are using a focalmin, for example, it will determine the minimum value and assign it to the middle value. Try subtracting the original raster from that raster and values of 0 should identify the cell location where the minimum occurred.

XanderBakker

If the OP needs to identify the lowest and highest position in a 3x3 window for each pixel I think it will need the Focal Flow to obtain that. Each pixel will obtain a value to points to the relative position where the highest or lowest pixel is located.

curtvprice

Here is how to locate each cell that is the highest or lowest value in its own 3x3 neighborhood. Not sure this is exactly what you want, but I thought I'd throw it out there.

The expressions below are formatted for the Raster Calculator tool. BTW, I used "" for neighborhood to use the default, NbrRectangle(3,3).

<SPAN class="comment token"># Cells that are the lowest of the 3x3 around that cell</SPAN>
Con<SPAN class="punctuation token">(</SPAN>FocalStatistics<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"MINIMUM"</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="comment token"># Cells that are the highest of the 3x3 around that cell</SPAN>
Con<SPAN class="punctuation token">(</SPAN>FocalStatistics<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"MAXIMUM"</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"in_grid"</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

FidelTedla

Dan_Patterson‌, xander_bakker‌, curtvprice‌

Thank you all for the help so far.

The suggested methods are unfortunately not doing what I want to do. This is mainly because the neighborhood zone is overlapping as the operation moves from one cell to another cell. The minimum cell for the first central cell will change its value to the minimum value for its own neighborhood as the operation moves from cell to cell. As a result subtracting the minimum raster from the original raster (or the method suggested by Curtis) will not give me the locations of all the minimum cells for each neighborhood zone.

Any more suggestions are appreciated.

Cheers

Fidel

XanderBakker

Have you tried the Flow Direction tool yet? It will return the lowest value for each pixel in a 3x3 neighborhood.

curtvprice

How about Block Statistics? This works with neighborhoods that do not overlap. I suspect this still isn't what you want though, since this is around the central cell again. Can you explain your use case -- what exactly are trying to do?

# Cells that are the lowest of the 3x3 around that cell
Con(BlockStatistics("in_grid", "", "MINIMUM") == "in_grid"), "in_grid")
# Cells that are the highest of the 3x3 around that cell
Con(BlockStatistics("in_grid", "", "MAXIMUM") == "in_grid", "in_grid")‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

All these Spatial Analyst raster operators output values of the central cell of a window, if the procedure Xander Bakker suggests (messing with FocalFlow) won't do it, it seems likely Dan Patterson's suggestion of numpy arrays is the only way to do what you want. There is a useful cookbook in the help on how to do cell by cell neighborhood stuff in numpy:

NumPyArrayToRaster—Help | ArcGIS Desktop

Back in the day, Spatial Analyst (ArcInfo Workstation GRID) supported neighorhood notation, but it was pretty slow and limited, this functionality is now covered by working with numpy arrays.

FidelTedla

Unfortunately Focal flow and Flow Direction are not working for me.

FidelTedla

Dan_Patterson‌, curtvprice‌, xander_bakker‌

I am trying to find upper and lower reservoir locations for potential pumped storage hydropower sites in a large area. My input is a Digital Elevation Model. So if I use a non-overlapping neighborhood, I will miss many possible upper and lower reservoir combinations in which one of the reservoirs lies in one neighborhood and the other reservoir in the adjacent neighborhood.

I am not familiar with NumPy Arrays and would really appreciate any help.

Thanks

Fidel

DanPatterson_Retired

Is this what you are looking for?

Over the DEM with transparency

FidelTedla

This is not what I am looking for. This is the original raster minus the Focal Min raster. As explained in one of my posts above this is not giving me what I am looking for. I am looking for the location of the min or max for each central cell. That means the number of min or max locations to be identified must be equal to the number of cells in the original raster.

DanPatterson_Retired

So, let me get this straight, for every 3x3 moving window, you want the location of the min within that moving window?

Lets look at the top 6 rows and columns. Here they are in array form. Array 'a' is the original dem, with the top row being a nodata row)

a<SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="number token">6</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">:</SPAN><SPAN class="number token">6</SPAN><SPAN class="punctuation token">]</SPAN>&nbsp; <SPAN class="comment token"># original dem with nodata row</SPAN>
array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">32768</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN>&nbsp;&nbsp; <SPAN class="number token">619</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">606</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">592</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">581</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">569</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">580</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN>&nbsp;&nbsp; <SPAN class="number token">602</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">592</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">581</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">572</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">579</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN>&nbsp;&nbsp; <SPAN class="number token">579</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">571</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">564</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">583</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN>&nbsp;&nbsp; <SPAN class="number token">552</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">551</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">562</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">575</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">592</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN>&nbsp;&nbsp; <SPAN class="number token">537</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">561</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">575</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">590</SPAN><SPAN class="punctuation token">,</SPAN>&nbsp;&nbsp;&nbsp; <SPAN class="number token">600</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN>int16<SPAN class="punctuation token">)</SPAN>

amin<SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="number token">6</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">:</SPAN><SPAN class="number token">6</SPAN><SPAN class="punctuation token">]</SPAN>&nbsp; <SPAN class="comment token"># minimum using a 3x3 moving window </SPAN>
array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">606</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">592</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">581</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">569</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">569</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">569</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN><SPAN class="number token">592</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">581</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">572</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN><SPAN class="number token">571</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN><SPAN class="number token">551</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">562</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">563</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN><SPAN class="number token">537</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">537</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">562</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">564</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">[</SPAN><SPAN class="number token">537</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">537</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">549</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">562</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">575</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN>uint16<SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Now for the top 3x3 window, the minimum is 581 as can be seen by what is returned by the focal min. Do you want the location of the minimum? Since there are 2 locations for that one core cell as you will notice. Do you want the one on the top row, 3rd column or the 581 on the 3rd row, 3rd column... or both. It makes a difference, but is doable, if you can explain why that precision in location is needed.

So... if none of that applies, what is the number you want in the example above.

FidelTedla

Thanks Dan. Yes, for every moving window I want the location of the minimum cell in the original raster (not in the focal min raster).

In the above example if we look at the array of the original raster, for the top 3x3 window (central cell 606 in original raster) the minimum is 581 and its location in the original raster is 3rd row and 3rd column. For the next 3x3 window moving to the right (central cell 592 in original raster) the minimum is 572 and its location in the original raster is 3rd row and 4th column.

But if it happens that there are 2 minimum values within a 3x3 window in the original raster, then I would want to know the locations of both.

The reason for wanting to know the exact location of the minimum values is that I will later use criteria to screen those locations in terms of their (terrain's) suitability to construct a reservoir at those locations.

I hope this helps.

FidelTedla

The 3x3 window is just as an example. My real neighborhood window is going to have a radius of few kilometers. By having a moving window I am making sure that there is an overlap between the windows resulting in combinations of min or max locations from different windows.

My aim at this point is just to find the areas where there is level difference (using the focal range tool) and locate the highest and lowest points. As mentioned above, I will later apply other criteria to determine their suitability to construct reservoirs, nearness to water sources...etc.

The raster I sent you is just a very small part of my input DEM. My real DEM is as big as a country the size of Germany.

DanPatterson_Retired

Then you need to use block values and return the minimum location within each block.

Assuming that the sample data you sent represents your moving/block window size, then the following would apply.

block size 128 rows x 229 columns

minimum value 355

location within block 113, 226

Now as the block moves over another 128 columns a new min is located and its location.

At the end of this you will have the location ... or locations of the minimum within each block.

This is the only way you can maintain the cell size while finding the minimum within each block.

At the end, your whole study area will have a bunch of values... but if you want to locate dams for reservoirs, you would have been better off using the Hydro tools and determine the subbasins and stream network within.

am_msk <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>ma<SPAN class="punctuation token">.</SPAN>masked_values<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">,</SPAN> value<SPAN class="operator token">=</SPAN>msk0<SPAN class="punctuation token">)</SPAN>&nbsp;&nbsp; <SPAN class="comment token"># input array accounting for nodata values</SPAN>

am_msk<SPAN class="punctuation token">.</SPAN>shape&nbsp; <SPAN class="comment token"># the number of rows and columns of your 'block window'</SPAN>
<SPAN class="punctuation token">(</SPAN><SPAN class="number token">128</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">229</SPAN><SPAN class="punctuation token">)</SPAN>

min_val <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>nanmin<SPAN class="punctuation token">(</SPAN>am_msk<SPAN class="punctuation token">)</SPAN>&nbsp; <SPAN class="comment token"># the minimum value in the block</SPAN>
min_val
<SPAN class="number token">355</SPAN>

loc <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>where<SPAN class="punctuation token">(</SPAN>am_msk <SPAN class="operator token">==</SPAN> min_val<SPAN class="punctuation token">)</SPAN>&nbsp; <SPAN class="comment token"># the row, column location within that block</SPAN>
loc
<SPAN class="punctuation token">(</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">113</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN>int64<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">226</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> dtype<SPAN class="operator token">=</SPAN>int64<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

XanderBakker

This thread has triggered my attention and I wanted to try something, just to get an idea of what we are talking about.

I created a python script that evaluates the largest drop in a moving window of 5x5 (still pretty small) to see what is possible, using a small extent of the data:

I converted the DEM into a point file and added the row and column numbers to it using the ($$RowMap and $$ColMap) in Python followed by the Extract Multivalues to Points tool.

Based on that data I created the script below where it travers through each center pixel (point) and extracts the values of the 5x5 neighborhood. It determines the min and max values and corresponding locations and generates a 3D polyline with attributes on drop (max - min) and some other stats.

If I color the lines by drop value and apply a minimum drop for the polyline to be generated (25m) this is the result:

I you look at a part of the area closer (showing only the largest drop values) you can see the effect:

Comparing it to a simple slope map:

and the lines on top of the slope raster

The code I used for this is listed below:

<SPAN class="comment token">#-------------------------------------------------------------------------------</SPAN>
<SPAN class="comment token"># Name:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; hydropower2.py</SPAN>
<SPAN class="comment token"># Purpose:</SPAN>
<SPAN class="comment token">#</SPAN>
<SPAN class="comment token"># Author:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Xander</SPAN>
<SPAN class="comment token">#</SPAN>
<SPAN class="comment token"># Created:&nbsp;&nbsp;&nbsp;&nbsp; 05-06-2017</SPAN>
<SPAN class="comment token">#-------------------------------------------------------------------------------</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">main</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">import</SPAN> arcpy
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">import</SPAN> os
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>overwriteOutput <SPAN class="operator token">=</SPAN> <SPAN class="token boolean">True</SPAN>

&nbsp;&nbsp;&nbsp; fc <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GeoNet\HydroPower\data.gdb\points_dem_small'</SPAN>
&nbsp;&nbsp;&nbsp; fld_dem <SPAN class="operator token">=</SPAN> <SPAN class="string token">'grid_code'</SPAN>
&nbsp;&nbsp;&nbsp; fld_row <SPAN class="operator token">=</SPAN> <SPAN class="string token">'row'</SPAN>
&nbsp;&nbsp;&nbsp; fld_col <SPAN class="operator token">=</SPAN> <SPAN class="string token">'col'</SPAN>

&nbsp;&nbsp;&nbsp; fc_out <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GeoNet\HydroPower\data.gdb\drop_lines3'</SPAN>
&nbsp;&nbsp;&nbsp; fld_minh <SPAN class="operator token">=</SPAN> <SPAN class="string token">"MinHeight"</SPAN>
&nbsp;&nbsp;&nbsp; fld_maxh <SPAN class="operator token">=</SPAN> <SPAN class="string token">"MaxHeight"</SPAN>
&nbsp;&nbsp;&nbsp; fld_drop <SPAN class="operator token">=</SPAN> <SPAN class="string token">"DropHeight"</SPAN>
&nbsp;&nbsp;&nbsp; fld_slope <SPAN class="operator token">=</SPAN> <SPAN class="string token">"Slope"</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># settings</SPAN>
&nbsp;&nbsp;&nbsp; min_drop <SPAN class="operator token">=</SPAN> <SPAN class="number token">25</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># create a featureclass and fill with drop line</SPAN>
&nbsp;&nbsp;&nbsp; ws<SPAN class="punctuation token">,</SPAN> fc_name <SPAN class="operator token">=</SPAN> os<SPAN class="punctuation token">.</SPAN>path<SPAN class="punctuation token">.</SPAN>split<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; sr <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>Describe<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN>spatialReference
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>CreateFeatureclass_management<SPAN class="punctuation token">(</SPAN>ws<SPAN class="punctuation token">,</SPAN> fc_name<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"POLYLINE"</SPAN><SPAN class="punctuation token">,</SPAN> None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"DISABLED"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"ENABLED"</SPAN><SPAN class="punctuation token">,</SPAN> sr<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">,</SPAN> fld_minh<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"DOUBLE"</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">,</SPAN> fld_maxh<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"DOUBLE"</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">,</SPAN> fld_drop<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"DOUBLE"</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">,</SPAN> fld_slope<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"DOUBLE"</SPAN><SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp; flds <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>fld_row<SPAN class="punctuation token">,</SPAN> fld_col<SPAN class="punctuation token">,</SPAN> fld_dem<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; dct <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="string token">'r{0}c{1}'</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">(</SPAN>r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">3</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">,</SPAN> flds<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">}</SPAN>

&nbsp;&nbsp;&nbsp; rows <SPAN class="operator token">=</SPAN> max<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN>fld_row<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; cols <SPAN class="operator token">=</SPAN> max<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>r<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN>fld_col<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN> <SPAN class="string token">"rows:"</SPAN><SPAN class="punctuation token">,</SPAN> rows
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN> <SPAN class="string token">"cols:"</SPAN><SPAN class="punctuation token">,</SPAN> cols

&nbsp;&nbsp;&nbsp; flds <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> fld_minh<SPAN class="punctuation token">,</SPAN> fld_maxh<SPAN class="punctuation token">,</SPAN> fld_drop<SPAN class="punctuation token">,</SPAN> fld_slope<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>InsertCursor<SPAN class="punctuation token">(</SPAN>fc_out<SPAN class="punctuation token">,</SPAN> flds<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> curs<SPAN class="punctuation token">:</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cnt <SPAN class="operator token">=</SPAN> <SPAN class="number token">0</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; drop_max <SPAN class="operator token">=</SPAN> <SPAN class="number token">0</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">,</SPAN> rows <SPAN class="operator token">+</SPAN> <SPAN class="number token">1</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> c <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">,</SPAN> cols <SPAN class="operator token">+</SPAN> <SPAN class="number token">1</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cnt <SPAN class="operator token">+=</SPAN> <SPAN class="number token">1</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> cnt <SPAN class="operator token">%</SPAN> <SPAN class="number token">5000</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN> <SPAN class="string token">"Processing"</SPAN><SPAN class="punctuation token">,</SPAN> cnt
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lst <SPAN class="operator token">=</SPAN> getListNeighbors<SPAN class="punctuation token">(</SPAN>dct<SPAN class="punctuation token">,</SPAN> r<SPAN class="punctuation token">,</SPAN> c<SPAN class="punctuation token">,</SPAN> rows<SPAN class="punctuation token">,</SPAN> cols<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; min_val <SPAN class="operator token">=</SPAN> getmin<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; max_val <SPAN class="operator token">=</SPAN> getmax<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; drop <SPAN class="operator token">=</SPAN> max_val <SPAN class="operator token">-</SPAN> min_val
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lst_pos_min <SPAN class="operator token">=</SPAN> getPositions<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> min_val<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lst_pos_max <SPAN class="operator token">=</SPAN> getPositions<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> max_val<SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> drop <SPAN class="operator token">>=</SPAN> min_drop<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; min_d <SPAN class="operator token">=</SPAN> <SPAN class="number token">25</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> pos_min <SPAN class="keyword token">in</SPAN> lst_pos_min<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> pos_max <SPAN class="keyword token">in</SPAN> lst_pos_max<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; d <SPAN class="operator token">=</SPAN> RelativeDistance<SPAN class="punctuation token">(</SPAN>pos_min<SPAN class="punctuation token">,</SPAN> pos_max<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> d <SPAN class="operator token"><</SPAN> min_d<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; min_d <SPAN class="operator token">=</SPAN> d
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pos_h <SPAN class="operator token">=</SPAN> pos_max
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pos_l <SPAN class="operator token">=</SPAN> pos_min
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; polyline <SPAN class="operator token">=</SPAN> CreatePolyline<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> pos_h<SPAN class="punctuation token">,</SPAN> pos_l<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; curs<SPAN class="punctuation token">.</SPAN>insertRow<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN>polyline<SPAN class="punctuation token">,</SPAN> min_val<SPAN class="punctuation token">,</SPAN> max_val<SPAN class="punctuation token">,</SPAN> drop<SPAN class="punctuation token">,</SPAN> float<SPAN class="punctuation token">(</SPAN>drop<SPAN class="punctuation token">)</SPAN><SPAN class="operator token">/</SPAN>float<SPAN class="punctuation token">(</SPAN>d<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> drop <SPAN class="operator token">></SPAN> drop_max<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; drop_max <SPAN class="operator token">=</SPAN> drop

&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN> <SPAN class="string token">"drop_max:"</SPAN><SPAN class="punctuation token">,</SPAN> drop_max


<SPAN class="keyword token">def</SPAN> <SPAN class="token function">CreatePolyline</SPAN><SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> pos_h<SPAN class="punctuation token">,</SPAN> pos_l<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; tpl_h <SPAN class="operator token">=</SPAN> GetItemOnTuple<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> pos_h<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; tpl_l <SPAN class="operator token">=</SPAN> GetItemOnTuple<SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> pos_l<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; pntg1 <SPAN class="operator token">=</SPAN> tpl_h<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; pntg2 <SPAN class="operator token">=</SPAN> tpl_l<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; sr <SPAN class="operator token">=</SPAN> pntg1<SPAN class="punctuation token">.</SPAN>spatialReference
&nbsp;&nbsp;&nbsp; pnt1 <SPAN class="operator token">=</SPAN> pntg1<SPAN class="punctuation token">.</SPAN>firstPoint
&nbsp;&nbsp;&nbsp; pnt1<SPAN class="punctuation token">.</SPAN>Z <SPAN class="operator token">=</SPAN> tpl_h<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; pnt2 <SPAN class="operator token">=</SPAN> pntg2<SPAN class="punctuation token">.</SPAN>firstPoint
&nbsp;&nbsp;&nbsp; pnt2<SPAN class="punctuation token">.</SPAN>Z <SPAN class="operator token">=</SPAN> tpl_l<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>Polyline<SPAN class="punctuation token">(</SPAN>arcpy<SPAN class="punctuation token">.</SPAN>Array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>pnt1<SPAN class="punctuation token">,</SPAN> pnt2<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> sr<SPAN class="punctuation token">,</SPAN> <SPAN class="token boolean">True</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token boolean">False</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">GetItemOnTuple</SPAN><SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> tpl<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; x <SPAN class="operator token">=</SPAN> tpl<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; y <SPAN class="operator token">=</SPAN> tpl<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; index <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="operator token">-</SPAN><SPAN class="number token">1</SPAN><SPAN class="operator token">*</SPAN>y<SPAN class="operator token">+</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="operator token">*</SPAN><SPAN class="number token">5</SPAN> <SPAN class="operator token">+</SPAN> x <SPAN class="operator token">+</SPAN> <SPAN class="number token">2</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> lst<SPAN class="punctuation token">[</SPAN>index<SPAN class="punctuation token">]</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">RelativeDistance</SPAN><SPAN class="punctuation token">(</SPAN>tpl1<SPAN class="punctuation token">,</SPAN> tpl2<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">import</SPAN> math
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> math<SPAN class="punctuation token">.</SPAN>hypot<SPAN class="punctuation token">(</SPAN>tpl1<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">-</SPAN> tpl2<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> tpl1<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">-</SPAN> tpl2<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">getmin</SPAN><SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; lst2 <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>a<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> a <SPAN class="keyword token">in</SPAN> lst <SPAN class="keyword token">if</SPAN> a<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">!=</SPAN> None<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> min<SPAN class="punctuation token">(</SPAN>lst2<SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">getmax</SPAN><SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; lst2 <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>a<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> a <SPAN class="keyword token">in</SPAN> lst <SPAN class="keyword token">if</SPAN> a<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">!=</SPAN> None<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> max<SPAN class="punctuation token">(</SPAN>lst2<SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">getPositions</SPAN><SPAN class="punctuation token">(</SPAN>lst<SPAN class="punctuation token">,</SPAN> val<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; positions <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">5</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> c <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">5</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; positions<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN>c<SPAN class="number token">-2</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="number token">1</SPAN><SPAN class="operator token">*</SPAN><SPAN class="punctuation token">(</SPAN>r<SPAN class="number token">-2</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; result <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> i <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">25</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> val <SPAN class="operator token">==</SPAN> lst<SPAN class="punctuation token">[</SPAN>i<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; result<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN>positions<SPAN class="punctuation token">[</SPAN>i<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> result

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">getListNeighbors</SPAN><SPAN class="punctuation token">(</SPAN>dct<SPAN class="punctuation token">,</SPAN> ri<SPAN class="punctuation token">,</SPAN> ci<SPAN class="punctuation token">,</SPAN> rows<SPAN class="punctuation token">,</SPAN> cols<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; lst <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; prn <SPAN class="operator token">=</SPAN> <SPAN class="token boolean">True</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> r <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN>ri <SPAN class="operator token">-</SPAN> <SPAN class="number token">2</SPAN><SPAN class="punctuation token">,</SPAN> ri <SPAN class="operator token">+</SPAN> <SPAN class="number token">3</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> c <SPAN class="keyword token">in</SPAN> range<SPAN class="punctuation token">(</SPAN>ci <SPAN class="operator token">-</SPAN> <SPAN class="number token">2</SPAN><SPAN class="punctuation token">,</SPAN> ci <SPAN class="operator token">+</SPAN> <SPAN class="number token">3</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; rc <SPAN class="operator token">=</SPAN> <SPAN class="string token">'r{0}c{1}'</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>r<SPAN class="punctuation token">,</SPAN> c<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> rc <SPAN class="keyword token">in</SPAN> dct<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lst<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN>dct<SPAN class="punctuation token">[</SPAN>rc<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; prn <SPAN class="operator token">=</SPAN> <SPAN class="token boolean">False</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lst<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> None<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> lst


<SPAN class="keyword token">if</SPAN> __name__ <SPAN class="operator token">==</SPAN> <SPAN class="string token">'__main__'</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; main<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

You could apply this to larger moving windows, but I'm still not convinced by it...

DanPatterson_Retired

largest drop is useful... hasn't been an implementation since Eppl7 (waaaaay back). Often, it is the largest drop that is needed and not the D8 or other slope calculations. Now I will have to dredge up some stuff I worked on last year. When I get some time, I will update the Nu. Re with sabbatical musings on surface derivatives

AdityaKhare

Here's what worked for me:

1) I reclassified my raster and assigned "NoData" value to all classes except for the last one which had the highest cell values. Displaying this reclassified raster on my original raster helped identify regions which had the highest cell values.

2) Used the Extract By Attributes tool and created an SQL query to output pixel(s) with highest value.

I had one specific cell with the highest value and it naturally fell in the region covered by the raster in step 2, and was easy to spot.

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