I have downloaded data from the USGS to create a Map for a malaria risk in east africa but my question is only about the actuall Input in the Raster Calculator. I have a RFE Tiff that shows the Rainfall in the Area, the highest rainfall is within the value of 76 to 150 so I used the following expression in the Raster Calculator to get an Output with only these values: "ea06063_ea3606mod@1" >= 76 AND "ea06063_ea3606mod@1" <= 150. Unfortunately all I got as an Output was a black screen... Anybody knows what could be the mistake??

  • Try this ("ea06063_ea3606mod@1" >= 76) AND ("ea06063_ea3606mod@1" <= 150) – TsvGis Jul 27 '15 at 5:25

Assuming that these values between 76 and 150 exist at the map, the correct expression to do that is:

("ea06063_ea3606mod@1" >= 76 AND "ea06063_ea3606mod@1" <= 150)*("ea06063_ea3606mod@1")

Afterward, when you have the raster loaded in QGIS, in the layer properties unmark "no data value" and set 0 as your "Additional no data value".

  • This is just for my curiosity, but why *("ea06063_ea3606mod@1") at the end? – TsvGis Jul 27 '15 at 23:32
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    @TsvGis Because the first part of the expression produces only 1 (where the condition is valid) and 0 values (no valid condition). – xunilk Jul 27 '15 at 23:38
  • So if I understand correctly, by having *("ea06063_ea3606mod@1") at the end of the expression, allows the results to show the range of values between 76 and 150 rather than having the two values of 1 and 0 (True/False) – TsvGis Jul 27 '15 at 23:53
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    Yes and the 0 values are now the "no data value". – xunilk Jul 27 '15 at 23:57

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