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I have tried this several different ways and get lots of NaN.

I need to specify that in my raster 'test1', I want a certain set of values to equal 1 and the rest to equal zero. For instance, I want 1, 42, and 102 to equal 1 and the rest to equal zero.

I have tried:

"test1@1" = 1 OR "test1@1" = 42 OR "test1@1" = 102

as well a few other options.

Unfortunately, there seem to be no existing syntax guidelines for the raster calculator (if you know of some, please send me a link).

How do I make this work?

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  • Have you tried putting your logical statements in brackets (e.g. "("test1@1= 1”) OR..."). Additionally, you could also try just multiplying your statements by 1 and adding them instead of using logical OR.
    – Trevor J. Smith
    Feb 1, 2016 at 6:24
  • Yes, I have tried all of those options. All result in a new layer with all values = NaN.
    – Rebecca Schmidt-Jeffris
    Feb 2, 2016 at 14:41

1 Answer 1

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I have tried an equivalent syntax for my raster (200 x 200 and random values between 1 and 102):

"random_raster@1" = 1 OR "random_raster@1" = 42 OR "random_raster@1" = 102

and it works; as it could be see at the next image ('Zoom In' in a reduced area of output raster out3.tif to verify, with 'Value Tool' plugin, the values obtained).

enter image description here

In your case, it should work too.

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  • The created raster on mine only has undefined values, so nothing shows up. It might be an issue of versions. I have the latest version (Wien) and it looks like you are running Lyon. I can't find any bug reports of this particular issue online though.
    – Rebecca Schmidt-Jeffris
    Feb 2, 2016 at 14:34
  • I should also clarify that having just the first one alone "test1@1" = 1 works just fine.
    – Rebecca Schmidt-Jeffris
    Feb 2, 2016 at 14:46

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