[GIS] ArcGIS Raster to Polygon conversion not always outputting Class Names

arcgis-desktopraster-conversion

I'm having issues converting a cropland data layer using the conversion tools>>raster to polygon tool. I try to convert the data and select the field "class names" to assign values to the polygons in the output dataset. For some reason, about 95% of the time, the output dataset does not contain the field "class names" in the attribute table. About 5% of the time, it does convert correctly and includes the class names data, but I don't think I'm doing anything different. I need the class names to show up in the output shapefile.

Any suggestions?

I'm using ArcGIS for Desktop.

arcgis raster to polygon

Best Answer

Normally with ArcGIS Desktop you cannot have spaces in your field names. Try creating a new field (Add Field GP tool) and copying the "class names" values to the new field (Calculate Field GP tool). Then convert to polygon. If that fails you might try importing the TIF into a file geodatabase and then try converting to polygon.

Related Solutions

[GIS] Selecting raster values at random locations in a raster in python/arcgis

If I understand you correctly I think you can solve it like this (their are comments in the code that explain what is going on):

import numpy, arcpy, random

#Establish the extent which your random samples can be within
rangeX = (100, 2500000) # Enter the actual range in x values of your rasters * 100 in order to get coordinates with decimals
rangeY = (100, 2500000) # Enter the actual range in y values of your rasters * 100 in order to get coordinates with decimals
qty = 1000  # Enter in the number greater than random points you need


#Generate random x,y coordinates
randPoints = []
while len(randPoints) < qty:
    x = random.randrange(*rangeX)/100.0 # divide by 100.0 to be able to get coordinates with decimal values
    y = random.randrange(*rangeY)/100.0 # divide by 100.0 to be able to get coordinates with decimal values
    randPoints.append((x,y))

#Create dictionary of key and lists, list will house tuples of (x,y,z)
#Enter in actual classified values for dictionary keys
valueDict = {'Class1' : [],
             'Class2' : [],
             'Class3' : [],
             'Class4' : []}

######Get Rasters bands as well as cell height, width, origin info to be able to get
######index of x,y location in the numpy array
arcpy.env.workspace = inPath + '\\aster.img'
bands = arcpy.ListRasters()
Ras = arcpy.Raster(inPath + '\\aster.img')
originX = Ras.extent.upperLeft.X
originY = Ras.extent.upperLeft.Y
pixelWidth = Ras.meanCellWidth
pixelHeight = Ras.meanCellHeight

#Create a list that houses each raster array
bandsList = []
for i in bands:
    bandsList.append(arcpy.RasterToNumPyArray(i).astype(numpy.float32))

#loop over all of the random point locations and collect raster values at their
#locations if the dictionary entry for that value is not full populate it
#with a tuple of (x,y,z), keep going until each class is full
for i in randPoints:
    X = i[0]
    Y = i[1]
    xOffset = int((X-originX)/pixelWidth)
    yOffset = int(abs(Y-originY)/pixelHeight)
    for j in range(0,len(bands)):
       sampleValue = bandsList[j][yOffset, xOffset]
       for key in valueDict.keys():
           if sampleValue == key:
               if len(valueDict[key]) < 10:
                   valueDict[key].append((X, Y, sampleValue))
                   break
               else:
                   continue

This is a variation of a script that I have used to extract raster values at random x,y locations, so it may need some tweaking but I think the major elements are their to get the job done for you.

[GIS] Unable to open feature class Failed to execute (RasterToPolygon)

Although it is cut off in the output you posted it appears that you are trying to create a shapefile named nofptreprojected_2014121_geog.tif.shp which I suspect is not a valid shapefile name.

Try replacing:

arcpy.RasterToPolygon_conversion(raster, raster +".shp", "SIMPLIFY")

with:

arcpy.RasterToPolygon_conversion(raster, raster.replace("tif","shp"), "SIMPLIFY")

or even simpler - purely as a test:

arcpy.RasterToPolygon_conversion(raster, "test.shp", "SIMPLIFY")

Best Answer

Related Solutions

[GIS] Selecting raster values at random locations in a raster in python/arcgis

[GIS] Unable to open feature class Failed to execute (RasterToPolygon)

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