[Qgis-user] making mistakes with raster calculator

[Giacomo Fontanelli]

Dear forum

I use QGIS 2.8.1.

I have a raster map, Float32, pixel values range from -0.7 to 1.

I Would like to make a map with pixel having only two values:

pixels with values <= 0 should be 0

pixels with values > 0 should be 5.

the sintax

( "3_NDFI at 1" <= 0 ) =0 AND  ( "3_NDFI at 1" > 0 ) =5

doesn't work because it produces a map with only 0 values.

In order to reach my goal I must do

( "3_NDFI at 1" <= 0 ) =0 AND  ( "3_NDFI at 1" > 0 ) =1

then multiply result by 5.

What's the problem?
Is it possible to fulfil the purpose with only one raster operation?

Thank you very much
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