Resample doesn't work?

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Wed, 07/18/2018 - 11:21 am

Hi,

On Igor 8.0.0.10, 
I ran into a strange issue, where the once working resample/rate function no longer works for me.
When I executed it with a wave created with

make/n=1e6 test
resample/rate=1e5 test

I receive an error saying "the number of points in a wave must be between 0 and 21470 million.", while I think I was within the range.
Meanwhile, if I simply use resample/down=10, it gives me the correct result.
 

Would you mind checking? Thanks

From the help for Resample:

/RATE=sampRate
    Converts the output waveName  to the specified sampling rate frequency (normally Hz).
    The necessary upSample and downSample values for each waveName are computed internally as if you had executed:
RatioFromNumber (deltax(waveName) * sampRate)
                upSample = V_numerator
                downSample = V_denominator
    /RATE returns V_numerator and V_denominator set to these automatically-determined values for the last waveName.

The make/n=1e6 test command made a new wave with a deltax = 1.

/RATE=1e5 is asking Resample to interpolate to a rate (1/deltax) of 100,000 by interpolating 100,000 output points for each input data point.

1e5 * 1e6 = 1e11

21470 million aka 21470e6 = 2.147e+10

So Resample is reporting the correct error.

July 18, 2018 at 02:11 pm - Permalink