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Python script/expression for field calculator for converting bearings to directions?

bobcostanza

I have a double field with bearings/azimuths (numbers) and I need them in letter directions: N, NE, NW,etc. I would like to calculate them in a new field. I have searched high and low for the code to use in the field calculator but I have failed to figure it out.

Thanks,

Bob

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Accepted answers

DanPatterson_Retired

a head messer

<SPAN class="keyword token">import</SPAN> numpy <SPAN class="keyword token">as</SPAN> np
<SPAN class="keyword token">global</SPAN> a
<SPAN class="keyword token">global</SPAN> c
a <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN> <SPAN class="number token">45</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">135</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">225</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">315</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">360</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
c <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">compass</SPAN><SPAN class="punctuation token">(</SPAN>angle<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="string token">""" test """</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> c<SPAN class="punctuation token">[</SPAN>np<SPAN class="punctuation token">.</SPAN>digitize<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>angle<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> a<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>

useage

compass<SPAN class="punctuation token">(</SPAN>!YourFieldNameHere!<SPAN class="punctuation token">)</SPAN>&nbsp; <SPAN class="comment token"># using the python processor of course</SPAN>
<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

although I hate to use globals.

Now when you do this in python (TableToNumPyArray or FeatureClassToNumPyArray) you can get the results quickly or as a demo script

&nbsp;&nbsp;&nbsp; angles <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">44</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">46</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">134</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">136</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">224</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">226</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">314</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">316</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">359</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> i <SPAN class="keyword token">in</SPAN> angles<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"{} => {}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">,</SPAN> compass<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Yielding...

<SPAN class="number token">0</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">44</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">46</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">134</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">136</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">224</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">226</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">314</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">316</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">359</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</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>

Why use this? Because the next thing is that someone will want to narrow down things into 22.5 degree chunks (ie NNW or NNE etc etc)

To change the above, you just need to fiddle in some more compass bearings and compass designators.

All comments

JakeSkinner

Hi Bob,

If the lines represent the bearings/azimuth correctly you can add COGO fields to the feature class and then update the COGO attributes.

blake.terhune

The COGO stuff Jake Skinner‌ posted is worth looking into. If you just want something quick and custom, could expand on logic like this?

<SPAN class="keyword token">if</SPAN> in_field_val <SPAN class="operator token">>=</SPAN> <SPAN class="number token">0</SPAN> <SPAN class="operator token">and</SPAN> in_field_val <SPAN class="operator token"><</SPAN> <SPAN class="number token">90</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; out_dir <SPAN class="operator token">=</SPAN> <SPAN class="string token">"N"</SPAN>
<SPAN class="keyword token">elif</SPAN> in_field_val <SPAN class="operator token">>=</SPAN> <SPAN class="number token">90</SPAN> <SPAN class="operator token">and</SPAN> in_field_val <SPAN class="operator token"><</SPAN> <SPAN class="number token">180</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; out_dir <SPAN class="operator token">=</SPAN> <SPAN class="string token">"E"</SPAN>
<SPAN class="keyword token">elif</SPAN> in_field_val <SPAN class="operator token">>=</SPAN> <SPAN class="number token">180</SPAN> <SPAN class="operator token">and</SPAN> in_field_val <SPAN class="operator token"><</SPAN> <SPAN class="number token">270</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; out_dir <SPAN class="operator token">=</SPAN> <SPAN class="string token">"S"</SPAN>
<SPAN class="keyword token">elif</SPAN> in_field_val <SPAN class="operator token">>=</SPAN> <SPAN class="number token">270</SPAN> <SPAN class="operator token">and</SPAN> in_field_val <SPAN class="operator token"><</SPAN> <SPAN class="number token">360</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; out_dir <SPAN class="operator token">=</SPAN> <SPAN class="string token">"W"</SPAN>
<SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; out_dir <SPAN class="operator token">=</SPAN> None<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>

DanPatterson_Retired

a head messer

<SPAN class="keyword token">import</SPAN> numpy <SPAN class="keyword token">as</SPAN> np
<SPAN class="keyword token">global</SPAN> a
<SPAN class="keyword token">global</SPAN> c
a <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN> <SPAN class="number token">45</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">135</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">225</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">315</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">360</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
c <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">compass</SPAN><SPAN class="punctuation token">(</SPAN>angle<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="string token">""" test """</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> c<SPAN class="punctuation token">[</SPAN>np<SPAN class="punctuation token">.</SPAN>digitize<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>angle<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> a<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>

useage

compass<SPAN class="punctuation token">(</SPAN>!YourFieldNameHere!<SPAN class="punctuation token">)</SPAN>&nbsp; <SPAN class="comment token"># using the python processor of course</SPAN>
<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

although I hate to use globals.

Now when you do this in python (TableToNumPyArray or FeatureClassToNumPyArray) you can get the results quickly or as a demo script

&nbsp;&nbsp;&nbsp; angles <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">44</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">46</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">134</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">136</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">224</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">226</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">314</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">316</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">359</SPAN><SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> i <SPAN class="keyword token">in</SPAN> angles<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"{} => {}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">,</SPAN> compass<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Yielding...

<SPAN class="number token">0</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">44</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">46</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">134</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">136</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">224</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">226</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">314</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">316</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">359</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</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>

Why use this? Because the next thing is that someone will want to narrow down things into 22.5 degree chunks (ie NNW or NNE etc etc)

To change the above, you just need to fiddle in some more compass bearings and compass designators.

bobcostanza

Thanks,

I am not working with points. I think I am in need of an if/else python

script.

Bob

bobcostanza

Isn't a if/else statement possible?

I need to look this over more.

DanPatterson_Retired

you copy the first block i posted just like you would any function in the codeblock area (including all lines 1-8)

Then I gave you the expression box syntax (make sure you use the python parser in the field calculator), and replace the !YourFieldNameHere! with your field name surrounded by exclamation marks..

The other two blocks are just demo scripts I used on my iThingy with Pythonista version 3.5, but it should still work with python 2.7

bobcostanza

Blake,

so, I don't need to check off the code block in field calculator, i.e., I

don't need the pre-logic script code and the other part?

thanks,

Bob

DanPatterson_Retired

when you are using a code block, then you need to show the code block just like in the picture

Calculate Field examples—Help | ArcGIS for Desktop in the code block section.

I use python as everyone will at some stage

DarrenWiens2

Very similar to other solutions that could be adapted to the field calculator:

Python parser

Expression:

myfunc<SPAN class="punctuation token">(</SPAN> !bearing! <SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

Codeblock:

dict <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">90</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">90</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">180</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">180</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">270</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">270</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">360</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">}</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">myfunc</SPAN><SPAN class="punctuation token">(</SPAN>bearing<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp; <SPAN class="keyword token">for</SPAN> k<SPAN class="punctuation token">,</SPAN>v <SPAN class="keyword token">in</SPAN> dict<SPAN class="punctuation token">.</SPAN>iteritems<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> bearing <SPAN class="operator token">>=</SPAN> v<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">and</SPAN> bearing <SPAN class="operator token"><</SPAN> v<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> k<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

DanPatterson_Retired

Darren... just shift your dictionary by 45 degrees since N-ish is 315 to 45, E-ish 45 to 135

DarrenWiens2

Ahhh, yes that's right. Well, you get the idea.

blake.terhune

Yeah, I did the same thing

DanPatterson_Retired

rather than messing up the original script post.

Direction (one variant of many... wiki it for the others)

Cardinal Degree range
N 348.75 - 11.25
NNE 11.25 - 33.75
NE 33.75 - 56.25
ENE 56.25 - 78.75
E 78.75 - 101.25
ESE 101.25 - 123.75
SE 123.75 - 146.25
SSE 146.25 - 168.75
S 168.75 - 191.25
SSW 191.25 - 213.75
SW 213.75 - 236.25
WSW 236.25 - 258.75
W 258.75 - 281.25
WNW 281.25 - 303.75
NW 303.75 - 326.25
NNW 326.25 - 348.75

<SPAN class="keyword token">import</SPAN> numpy <SPAN class="keyword token">as</SPAN> np
<SPAN class="keyword token">global</SPAN> a
<SPAN class="keyword token">global</SPAN> c
a <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>arange<SPAN class="punctuation token">(</SPAN><SPAN class="number token">11.25</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">360</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">22.5</SPAN><SPAN class="punctuation token">)</SPAN>
c <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NNE'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NE'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'ENE'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'ESE'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SE'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SSE'</SPAN><SPAN class="punctuation token">,</SPAN> 
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SSW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'SW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'WSW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'WNW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NNW'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">compass</SPAN><SPAN class="punctuation token">(</SPAN>angle<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="string token">""" test """</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> c<SPAN class="punctuation token">[</SPAN>np<SPAN class="punctuation token">.</SPAN>digitize<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>angle<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> a<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>

Expression for the field calculator

compass<SPAN class="punctuation token">(</SPAN>!Field_with_the_angles!<SPAN class="punctuation token">)</SPAN>&nbsp; <SPAN class="comment token"># using the python processor of course</SPAN>
<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

For general testing or for single entry use and testing.

angles <SPAN class="operator token">=</SPAN> np<SPAN class="punctuation token">.</SPAN>arange<SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">360</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">20</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token">#[0, 44, 46, 134, 136, 224, 226, 314, 316, 359]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> i <SPAN class="keyword token">in</SPAN> angles<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"{} => {}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">,</SPAN> compass<SPAN class="punctuation token">(</SPAN>i<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Result

<SPAN class="number token">0</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'N'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">20</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'NNE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">40</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'NE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">60</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'ENE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">80</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">100</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'E'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">120</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'ESE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">140</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">160</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SSE'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">180</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'S'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">200</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SSW'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">220</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SW'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">240</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'WSW'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">260</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">280</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'W'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">300</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'WNW'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">320</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'NW'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="number token">340</SPAN> <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'NNW'</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>

bobcostanza

I don't know what are appropriate responses for this new forum but I want to thank you all for your help. I should be able to give the scripts a test on Monday. I do need to calculate NNE, SSW, WSW, etc.

It appears that the new forum is a collaborative effort between a bunch of people? I'll try to read about it.

I am really surprised that my question was new. I thought a half hour of Googling and I'd find how to do it.

Bob

DarrenWiens2

It depends what you were searching for. Does it ever work to search for a ready-made script that does exactly what you want? You really just need a "Python if statement" (or more likely, several), which produces endless useful search results explaining how to do what you need to do, if you look at the more general problem.

bobcostanza

Dan, I just got around to working with the script you provided. Should your last expression from Sep 23, 2016 10:38 AM work as is except for my field name with the angles?

Thanks

DanPatterson_Retired

make a text field to put the result in.... the !YourFieldNameWiththeAnglesGoesInTheExpression!

goes between the double ! marks.

bobcostanza

Oh, crap. I think I made it a number field!

Thanks Dan, I'll try again on Monday.

Bob

DanPatterson_Retired

FYI I haven't accounted for changes in the polar axis since this thread was begun

bobcostanza

Dan,

the field I was using your script in was a text field but it still failed to execute. One of the error messages in the Geoprocessing results is "The field is not nullable. [dir] ". Is that the problem?

dir is the field I was working on, Bearing is the field with the angles

Thanks a million,

Bob

DanPatterson_Retired

you didn't switch to the python parser did you

bobcostanza

Dan,

The field is text, the parser is python. Attached is a screenshot of what

it looks like. I am using the script from Sep 23, 2016 10:38 AM

I am just copying and pasting the script, other then specifying the

bearing field do I need to do anything else?

Thanks again,

Bob

python script capture.JPG

DanPatterson_Retired

number is selected as the field type instead of

A small but important fact... your 'bearings' appear to go from -180 to 180 instead of 0-360 as expected by the code. I think the angles are relative to the X axis and not compass bearings. This will have to be fixed on your end.

I could fix the code to do this but it would go from a simple expression expecting a specific input to one that accommodates all possible variants of angle types.

jarbaslima55dias

I am using the following script in ArcGIS 10.3 to calculate Quadrant (in the format angle/NE/SE/SW/NW) from azimuth. See example in:

: https://support.esri.com/pt-br/knowledge-base/instruo-calcular-a-direo-da-linha-em-lote-usando-a-calc-000015375

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

def quadrant(NorthAzimuth):

if ((NorthAzimuth>=0) & (NorthAzimuth<90)):

quad = 'N '+str(NorthAzimuth)+' E'

elif ((NorthAzimuth>=90) & (NorthAzimuth<180)):

quad = 'S '+str(180-NorthAzimuth)+' E'

elif ((NorthAzimuth>=180) & (NorthAzimuth<270)):

quad = 'S '+str(NorthAzimuth-180)+' W'

else:

quad = 'N '+str(360-NorthAzimuth)+' W'

return quad

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

The box Show Codeblock is cheked. This script is copied in the box Pre-logic Script Code. In the box below - "Quadrant = " is typed quadrant (!NorthAzimuth!).

My polyline shape file contains the followings fields: Start_X (double), Start_Y (double), End_X (double), End_Y (Double), Compriment (double) - polyline lenght, and NorthAzimu (double) - azimuth in degrees.

I already replace the term NorthAzimuth of script with NorthAzimu, but without sucess.

The script always returns an error message.

Please, where is the error?

window2.jpg

window1.jpg

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