topic Quantile statistics of z values in a shapefile in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/quantile-statistics-of-z-values-in-a-shapefile/m-p/696008#M10130 <HTML><HEAD></HEAD><BODY><P>I have a raster dataset containing z values. Besides this i have a shapefile with +/- 50.000 records. Each record represents an area of 400m2. For each record i would like to get the maximum height within the record. Using zonal statistics&nbsp; gives me the MAX z value of the raster within each record of the shapefile. To rule out outlyers in the rasterdataset instead of the maximum value of a cell within each record i would like the quantile 99% value. I reckon this should be possible&nbsp;but I cant seem to figure out how. Im guessing pythons numpy.quantile&nbsp;will be needed.</P><P><IMG class="image-1 jive-image" src="https://community.esri.com/legacyfs/online/450795_pastedImage_1.png" /></P></BODY></HTML> Wed, 19 Jun 2019 14:09:51 GMT TimDubbeldam 2019-06-19T14:09:51Z Quantile statistics of z values in a shapefile https://community.esri.com/t5/arcgis-spatial-analyst-questions/quantile-statistics-of-z-values-in-a-shapefile/m-p/696008#M10130 <HTML><HEAD></HEAD><BODY><P>I have a raster dataset containing z values. Besides this i have a shapefile with +/- 50.000 records. Each record represents an area of 400m2. For each record i would like to get the maximum height within the record. Using zonal statistics&nbsp; gives me the MAX z value of the raster within each record of the shapefile. To rule out outlyers in the rasterdataset instead of the maximum value of a cell within each record i would like the quantile 99% value. I reckon this should be possible&nbsp;but I cant seem to figure out how. Im guessing pythons numpy.quantile&nbsp;will be needed.</P><P><IMG class="image-1 jive-image" src="https://community.esri.com/legacyfs/online/450795_pastedImage_1.png" /></P></BODY></HTML> Wed, 19 Jun 2019 14:09:51 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/quantile-statistics-of-z-values-in-a-shapefile/m-p/696008#M10130 TimDubbeldam 2019-06-19T14:09:51Z Re: Quantile statistics of z values in a shapefile https://community.esri.com/t5/arcgis-spatial-analyst-questions/quantile-statistics-of-z-values-in-a-shapefile/m-p/696009#M10131 <HTML><HEAD></HEAD><BODY><P>You have to convert the raster to a numpy array (arcpy.da.RasterToNumPyArray(….)</P><P>and if you have nodata values, then you should be using the 'nan' versions of either the percentile or quantile</P><P><A class="link-titled" href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.nanpercentile.html" title="https://docs.scipy.org/doc/numpy/reference/generated/numpy.nanpercentile.html">numpy.nanpercentile — NumPy v1.16 Manual</A> &nbsp;</P><P><A class="link-titled" href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.nanquantile.html" title="https://docs.scipy.org/doc/numpy/reference/generated/numpy.nanquantile.html">numpy.nanquantile — NumPy v1.16 Manual</A>&nbsp;</P><P>otherwise, their non-nan versions are fine.</P></BODY></HTML> Tue, 25 Jun 2019 03:36:25 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/quantile-statistics-of-z-values-in-a-shapefile/m-p/696009#M10131 DanPatterson_Retired 2019-06-25T03:36:25Z