Latest Contributions by EricRice

Run Zonal Statistics as Table.  First you need to create a zone though.  We will use your rainfallvolume raster to do this.  Open the Raster Calculator and input Int("RainfallVolume" * 0).  This will return an integer raster of all zero's (constant value) that is the exact size and shape of the rainfall data.  Use this raster as the input zones using the Value field.  Use the rainfall raster as the Input Value Raster, also using the Value field. -Eric ... View more

Hi, I've been using this script and I've got always horizontal and squared extents, even if my raster has a rotation angle and it doesn't fit this geometry. Is there any way to create this shapefile using rotation angles? Are there other scripts that could do that? Thank you. This sample tool, "creates a polygon index shapefile from raster extent boundaries", meaning it doesn't care about the radiometry.  If you want a footprint of the real pixels instead of just a box, you can create a Mosaic Dataset and build footprints by radiometry.  Here is a link with some graphics. Mosaic Dataset Footprints Regards, Eric ... View more

The maximum possible ObjectID value is 2,147,483,648. The ObjectID field is maintained by ArcGIS and guarantees a unique ID for each row in a table.  This is the limit of records in a table in theory.  However, since raster attribute tables outside of a geodatabase are maintained/created as .dbf files, they are subject to the 2gb limit on disk just like a shapefile's attribute table would be. Regards, Eric ... View more

Jamal, You can't have a feature class of point, line, or polygon without also having an attribute table.  "Fields" is something that is common to all of those and thus they have a shared UI.  Raster data on the other hand, does not always have a table.  Multiband imagery doesn't support tables, nor does 32 bit float.  Integer data can support a table, but depending on the data it may be built automatically or it could be up to you to run the Build Raster Attribute Table tool to force a table to be built.  Because of the lack of uniformity among the various types of raster data with respect to attribute tables, they do not have a shared "Fields" tab in the properties dialog. Regards, Eric ... View more

Here is the forumula to rescale your data. rescaled grid = [(grid - min value from grid) * (max scale value - min scale value) / (max value from grid - min value from grid)] + min scale value -Eric ... View more

Jay, You have quite a bit of overlap in the images.  Have you tried increasing the Shrink parameter when building footprints?  You should be able to shrink somewhat excessivley because of the amount of overlap.  It will be better than manually editing, which you can do using the tips above.  The mosaic dataset is the approach to take for resolving the image collars, but to serve it you must have the Image Extension regardless of whether you make an image service from the MD or if you make a map service with the MD in it.  Without the extension you are going to have to create a flat file on disk of the whole thing (a raster dataset), then publish that.  Basically, you run Copy Raster or Export Data from the UI, and input the mosaic dataset. Regards, Eric ... View more

Simon, The values you are receiving indicate that you are most likely mixing units of x & y with z.  I would guess your DEM is in a geographic coordinate system using units of decimal degrees, and your z (pixel) values are in meters/feet. To ensure accurate slope values you need to have x,y, and z all be in the same units.  So, what you need to do is run Project Raster and specify a coordinate system that has the same linear unit as your z units in the DEM. Regards, Eric ... View more

Jay, The first question is do you have licensing for the ArcGIS Server Image Extension?  Without it, you can only serve raster datasets, not mosaic datasets.  Removing the collars off the images shouldn't be that hard if you adjust the footprints of the mosaic dataset.  Eric ... View more

Zonal Statistics as Table works with 32 bit floating point rasters.  There is no table requirement for the input value raster.  We could not enforce a table requirement even if we wanted to because of the fact that you can input 32 bit float rasters.  All you needed to do was use your polygons as the zone features, and the Slope result (in 32 bit form) as input value raster, as well as set some of the environment settings per the documentation. As for the missing records, please review the last two bullet points in my previous post.  I'm pretty sure you are using polygons as the zone features, so you should also be setting the cell size to use for analysis within the environment settings.  This tip is included in the documentation I linked to earlier. The easiest way to guarantee results is to convert your polygons to a raster that has the same cell size as the DEM so the resolutions match.  This will also help you verify you have the correct number of zones in the raster - It should be the same as the number of polygons, assuming each polygon had a unique ID and a single polygon was not smaller than 10m squared, for your case.  If you continue to input polygons (which is completely ok) you should ensure that the results of the internal conversion will align properly with  the value raster, by checking that the extent and  snap raster are set appropriately in the environment settings and the  raster settings.  If you decide to convert ahead of time you also need to set the extent and snap raster to ensure alignment. The use of ObjectID or other reserved fields is also discussed in the tool documentation I linked to earlier. Best Regards, Eric ... View more

The Export Raster Data Tool (accessed through right click - Data - Export Data in ArcView) allows the user to select the "Use Renderer" option. This option seems to convert my 16bit tifs into 8bit tifs properly. I'm just going to throw this out there for everyone.  There is no conversion from 16 bit data to 8 bit data using the Export Dialog.  However, using the options "Use Renderer" and "Force RGB", there is a conversion from 16 bit data to an 8 bit picture of your data which is why it looks nearly identical.  Its similar to taking a screenshot.  Was this your goal? Why do you want to go from 16 bit to 8 bit? Best Regards, Eric ... View more

Matt, There is no requirement that the input value raster has an attribute table.  It is only required of the zone raster. Also, with regard to this comment: "I have converted the polygon layer to raster (not ideal as some of the polygons are smallish), and no success."  If you don't convert the polygon zones to raster, we do it anyway behind the scenes.  This is how the tool works.  Below are some key parts of the Usage Tips from the tool. The input value raster can be either integer or floating point. However,  when it is floating-point type, the zonal calculations for majority,  median, minority, and variety will not be computed. It is recommended to only use rasters as the zone input, as it offers  you greater control over the vector-to-raster conversion. This will help  ensure you consistently get the expected results. If the zone input is a feature dataset with relatively small features,  keep in mind that the resolution of the information needs to be  appropriate relative to the resolution of the value raster. If the areas  of single features are similar to or smaller than the area of single  cells in the value raster, in the feature-to-raster conversion some of  these zones may not be represented. If  the zone feature input has overlapping polygons, the zonal analysis  will not be performed for each individual polygon. Since the feature  input is converted to a raster, each location can only have one value. An alternative method is to process the zonal statistics iteratively for each of the polygon zones and collate the results. Here is the full documentation for the tool.  Zonal Statistics as Table Best Regards, Eric ... View more

Rui, I assume you have a DEM for your solar analysis.   You need to burn the buildings into the DEM.  Here is a tool to download to do it. Add Buildings into DEM Regards, Eric ... View more

One way I quickly thought of is to just convert the feature class to a shapefile.  Shapefile's do not support Null entries and automatically convert Null to zero.  Regards, Eric ... View more

Or you can just run the Con tool with the "Input true raster or constant value" set to 1.  See screenshot.  No 'where clause' with this technique. Regards, Eric ... View more

Greetings, I'd like to add one more thing aside from ensuring the x,y,z are all the same unit.  It is still technically possible to get slopes in excess of 100%, in particular if your data is in rugged terrain.  After all, a slope of 100% is equivalent to a 45 degree slope.  Knowing that degree slope ranges from 0 -90 (flat to vertical) we can easily infer slope can exceed 100%.  Our own graphics in the help system show a slope of 373% as an example output.  It may help if you review, How Slope Works. The reason your numbers are so high right now is because your dividing the rise (in feet/meters) by the run (in decimal degrees).  Essentially your denominator is a very small number compared to the rise value.  We also multiply the quotient by 100 making that large value even larger. Best Regards, Eric ... View more