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ExtractMultiValuesToPoints exhbits strange behavior

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2
08-15-2022 07:08 AM
WadeWall
Regular Contributor

Hi all,

I am trying to understand the behavior of ExtractMultiValuesToPoints when incorporated into an Arcgis tool.

I have used the function in an Arcpy standalone script, and it works just fine. However, after incorporating into a python tool, the stars have to be aligned just right for it to work. Included is a tool that I have created to extract values from a multiband raster into a new shapefile.

The issues are (1) I have to rename the bands because the tool generates new names not related to the raster bands, (2) if the shapefile is linked to the tool from a GIS workspace, the names aren't carried over, (3) rasters cannot be linked to from a GIS workspace and (4) ExtractMultiValuesToPoints has no option to preserve the original file (as far as I can tell). These are really just minor annoyances, so am wondering if I am somehow doing it wrong. Thanks for any information.

 

class Combine_labels_features(object):
    def __init__(self):
        """Define the tool (tool name is the name of the class)."""
        self.label = "07 Combine labels and features"
        self.description = "This tool combines the labels point shapefile (generated and QAQC'd) with the appropriate features file"
        self.canRunInBackground = False

    def getParameterInfo(self):
        """Define parameter definitions"""
        labels = arcpy.Parameter(
            displayName="labels file",
            name="labels",
            datatype="GPFeatureLayer",  
            parameterType="Required",
            direction="Input")
        labels.filter.list = ["Point"] 

        features = arcpy.Parameter(
            displayName="features (raster)",
            name="features",
            datatype= u'GPRasterLayer',  
            parameterType="Required",
            direction="Input")
        
        outfile = arcpy.Parameter(
            displayName="outfile",
            name="outFile",
            datatype="DEType",
            parameterType="Required",
            direction="Output")

        params = [labels,features,outfile]
        return params

    def isLicensed(self):
        """Set whether tool is licensed to execute."""
        return True

    def updateParameters(self, parameters):
        """Modify the values and properties of parameters before internal
        validation is performed.  This method is called whenever a parameter
        has been changed."""
        return

    def updateMessages(self, parameters):
        """Modify the messages created by internal validation for each tool
        parameter.  This method is called after internal validation."""
        return

    def execute(self, parameters, messages):
        """The source code of the tool."""
        labels = parameters[0].valueAsText
        infile = parameters[1].valueAsText
        outfile = parameters[2].valueAsText

        features = Raster(infile)

        rasters = [] ### holder for raster predictors
        nams = features.bandNames
        names = ["B_" + str(i+1) for i in range(0,len(nams))]

        for i in range(0,len(nams)):
            print(nams[i])
            tmplist = [infile + "\\" + nams[i],names[i]]
            rasters.append(tmplist)

        origNames = [field.name for field in arcpy.ListFields(labels)]
        
        arcpy.sa.ExtractMultiValuesToPoints(labels,infile,"BILINEAR")
        tmpfile = os.path.basename(tempfile.TemporaryFile().name)
        arcpy.management.CopyFeatures(labels,tmpfile,'', None, None, None)

        badNames = [field.name for field in arcpy.ListFields(tmpfile)]
        badNames = [x for x in badNames if x not in origNames]
        badNames.remove("OBJECTID")

        BandKey = {badNames[i]:nams[i] for i in range(len(badNames))} 

        for key, value in BandKey.items():
            print(key)
            print(value)
            arcpy.AlterField_management(tmpfile, key,value)

        ## add directly to initial labels. Should make copy if you want to preserve.
        ## ExtractMultiValuesToPoints is not behaving as it should. In Arcpy, the names from
        ## the original rasters carries through. Does not happen in the tool. Not sure why,
        arcpy.management.CopyFeatures(tmpfile,outfile,'', None, None, None)
        arcpy.Delete_management(tmpfile)
                
        return

 

 

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2 Replies
DanPatterson
MVP Esteemed Contributor

Extract Multi Values to Points (Spatial Analyst)—ArcGIS Pro | Documentation

regarding (4)

  • This tool modifies the input point features and may change its internal feature ID, which may be named ObjectID, FID, or OID. It is recommended that you include a unique ID field in the attribute table before performing the analysis.

OBJECTID is mentioned as well as shapefile, did you mean to include FID and OID for removal as well?


... sort of retired...
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WadeWall
Regular Contributor

For the purposes of the tool, ObjectID is not important, but I can see that in many cases it would be important.

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