topic Re: zonal statistics result is empty table in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/zonal-statistics-result-is-empty-table/m-p/52832#M735 <HTML><HEAD></HEAD><BODY><BLOCKQUOTE class="jive-quote">Hello <BR />I am trying to run zonal statistics<BR /><BR />zone data = buffered point data (buffer distance = 3km)<BR />raster layer = rainfall = a floating point file with values from 0 to 253.65<BR /><BR />the result I get back is an empty table. <BR /><BR />when I run the analysis on the point data only, i.e., not the buffered data, I do get results back. So this makes me think the raster layer is fine but it is the buffered point data file that is incorrect. <BR /><BR />A previous thread on a similar problem indicated the problem could be related to projections and cooridnate systems, so I had a look and although both files are set to WGS coordinate system, the data frame is in decimal degrees. <BR /><BR />Any thoughts? <BR /><BR />Thanks!</BLOCKQUOTE><BR /><BR /><SPAN>Zonal statistics is area-weighted (by counting cells), and buffers are dependent on accurate distance measurements. (Square degrees are not a very good measure of area, and having the system convert a buffer distance from meters to degrees on the fly is likely to give you invalid results.) </SPAN><BR /><BR /><SPAN>You'll likely have better luck if your raster and point data are projected (using Project and Project Raster) to a coordinate system, for example, UTM or Albers, before you do the analysis.</SPAN></BODY></HTML> Tue, 27 Mar 2012 04:30:09 GMT curtvprice 2012-03-27T04:30:09Z zonal statistics result is empty table https://community.esri.com/t5/arcgis-spatial-analyst-questions/zonal-statistics-result-is-empty-table/m-p/52831#M734 <HTML><HEAD></HEAD><BODY><SPAN>Hello </SPAN><BR /><SPAN>I am trying to run zonal statistics</SPAN><BR /><BR /><SPAN>zone data = buffered point data (buffer distance = 3km)</SPAN><BR /><SPAN>raster layer = rainfall = a floating point file with values from 0 to 253.65</SPAN><BR /><BR /><SPAN>the result I get back is an empty table. </SPAN><BR /><BR /><SPAN>when I run the analysis on the point data only, i.e., not the buffered data, I do get results back. So this makes me think the raster layer is fine but it is the buffered point data file that is incorrect. </SPAN><BR /><BR /><SPAN>A previous thread on a similar problem indicated the problem could be related to projections and cooridnate systems, so I had a look and although both files are set to WGS coordinate system, the data frame is in decimal degrees. </SPAN><BR /><BR /><SPAN>Any thoughts? </SPAN><BR /><BR /><SPAN>Thanks!</SPAN></BODY></HTML> Mon, 26 Mar 2012 20:19:45 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/zonal-statistics-result-is-empty-table/m-p/52831#M734 SThompson 2012-03-26T20:19:45Z Re: zonal statistics result is empty table https://community.esri.com/t5/arcgis-spatial-analyst-questions/zonal-statistics-result-is-empty-table/m-p/52832#M735 <HTML><HEAD></HEAD><BODY><BLOCKQUOTE class="jive-quote">Hello <BR />I am trying to run zonal statistics<BR /><BR />zone data = buffered point data (buffer distance = 3km)<BR />raster layer = rainfall = a floating point file with values from 0 to 253.65<BR /><BR />the result I get back is an empty table. <BR /><BR />when I run the analysis on the point data only, i.e., not the buffered data, I do get results back. So this makes me think the raster layer is fine but it is the buffered point data file that is incorrect. <BR /><BR />A previous thread on a similar problem indicated the problem could be related to projections and cooridnate systems, so I had a look and although both files are set to WGS coordinate system, the data frame is in decimal degrees. <BR /><BR />Any thoughts? <BR /><BR />Thanks!</BLOCKQUOTE><BR /><BR /><SPAN>Zonal statistics is area-weighted (by counting cells), and buffers are dependent on accurate distance measurements. (Square degrees are not a very good measure of area, and having the system convert a buffer distance from meters to degrees on the fly is likely to give you invalid results.) </SPAN><BR /><BR /><SPAN>You'll likely have better luck if your raster and point data are projected (using Project and Project Raster) to a coordinate system, for example, UTM or Albers, before you do the analysis.</SPAN></BODY></HTML> Tue, 27 Mar 2012 04:30:09 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/zonal-statistics-result-is-empty-table/m-p/52832#M735 curtvprice 2012-03-27T04:30:09Z