Eliminating values based on a null

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Eliminating values based on a null

Jenny Turner
Greetings

in my base map (called X) I have a few null values and, in Y map I want to eliminate pixels that match with null values in X. How can I do this? besides using mapcalc

Thanks
Jenny

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Re: Eliminating values based on a null

Marcello Gorini
>Jenny:
>
>in my base map (called X) I have a few null values and, in Y map I want to
>eliminate pixels that match with null values in X. How can I do this?
>besides using mapcalc

Hello Jenny,

I don't know if it is a coincidence, but your problem can be solved in the same way as Kim's problem.

You can use the module r.series with the -n flag. It will propagate the nulls among your input rasters. The method you use does not matter because the -n flag overrides it. So it would be like this:

r.series -n input=X,Y output=Y_without_X_nulls method=average (or any method)

Hope this helps,

Marcello.
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Re: Eliminating values based on a null

peifer
On 16/02/2011 18:12, Marcello Gorini wrote:

>
>> Jenny:
>>
>> in my base map (called X) I have a few null values and, in Y map I want to
>> eliminate pixels that match with null values in X. How can I do this?
>> besides using mapcalc
>
> r.series -n input=X,Y output=Y_without_X_nulls method=average (or any
> method)
>

Just curious: What exactly is the advantage of NOT using mapcalc?

Hermann
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