Tag Info

Hot answers tagged

3

As discovered in the comments, one row (value = 21) was selected before running Reclassify. The Reclassify tool only considered the selected row, therefore only reclassified those pixels where value = 21, to the new value, 2. Edit: it may be worth noting that there is no mention of whether Reclassify respects selections in the help page. I would be ...


3

You can use the Con (Spatial Analyst) tool to calculate the area of specified elevation values. In this example, I stated that I wanted all elevation values of a floating point DEM > 400 = 1, else = 0. The black and yellow image is the result (Figure 1). Then, simply open the attribute table and look at the count next to the Value = 1 row (Figure 2). ...


2

As mentioned by @Michael Miles-Stimson, the first step is to compute a new raster with the value of the minimum in your neighbourhood. This can be done using Focal Statistics tools. The second step consists in finding the values of the original raster that are equal to your maximum values. This can be done using the Con tool ...


2

There are several ways to approach this. One option is to use the Raster Calculator, as you indicated. I see that your NDVI values have been rescaled from floating point (-1 to 1) to unsigned 8-bit integer (0 - 255). This is the syntax you would use in the raster calculator: ("ndvi_1" + "ndvi_2" + "ndvi_3") / 3 You can also use Cell Statistics (Spatial ...


2

The data type of the columns I wished to pass to the spatial analyst kriging function where of type "text"... text can not be passed to kriging functions, and I needed to change these to integer values... I suppose a double would have also worked but I prefer long integer as some of the data was in the range of e^-5... two possible methods to solve this ...


2

I am late here, but this question was my entry into the forum as I was researching the same question. I think that the original poster may want to calculate for each cell the height above the first stream cell that would be reached by water flowing from the cell. So the 'nearest stream' is calculated along the downslope flow path, not euclidian distance. ...


1

Quick and dirty way would be to translate the XY points into a distance from river mouth, use that for river distance, and then graph the temperature as the Y value..If all you're doing is trying to get it to plot properly for that graphic. If you're trying to do something 3D, look into z values. If all you need to do is join grid to shapefile, convert ...


1

EDIT : The default output of line density is in kilometer per square kilometer. So the output of the tool is already what you are looking for (you don't need to divide it again by the size of the circle, this is done automatically). Note that the vector-based approach from @Anggik will be more precise, however you will not have overlapping window analysis.


1

in my point of view, you should decide your unit area (it could be county boundary or certain grid). after that, do some geoprocessing to divide roads in each unit area. Then you calculate each of roads length in each unit area and divide with the hectarage (or km2).


1

You need to create a hydrologically corrected (depressionless) DEM from your contours through interpolation to a raster DEM. Then you need to perform a flow accumulation operation, such that the pipes serve as the seed points and the downslope flowpaths issuing from these locations are traced. Many GIS have specific tools to perform this type of flowpath ...


1

If your elevation raster is integer, Build Raster Attribute Table. Then, select the rows in the table of interest, and look at the Statistics for the Count field (right-click 'Count' -> Statistics). The SUM value is the number of pixels selected. Multiply this value by the area of one pixel (raster layer properties -> Source tab -> cell size). Repeat with no ...


1

Maybe you could detail a bit more the attempts you made, in order to understand what happened. In any case, from my experience there is not a smooth pipeline to import things from PostGIS (or any OGC standard) to Hadoop GIS, which is a shame... ESRI has ticked the box of Free and Open Source Software by providing this tool (which by the way, it is one of ...



Only top voted, non community-wiki answers of a minimum length are eligible