Comparison between Matlab and Igor
Konstantinos Chatzipanagis
Fri, 02/27/2015 - 06:18 pm
I am calculating the second derivative of a particular data range regarding Raman spectra both with igor and matlab....I noticed that the amplitude is higher in Matlab with respect to igor.....it is also likely that the position of a peak revealed in the second derivative has 1 wavenumber difference between matlab and igor....this seems a bit strange to me since its the same data set. Any suggestions?
Thnaks,
Konstantinos
February 27, 2015 at 06:19 pm - Permalink
--Jim Prouty
Software Engineer, WaveMetrics, Inc.
February 27, 2015 at 08:29 pm - Permalink
Thanks for that......However, how can i choose between algorithms? I am basically using the differentiate option given and just do it.....How is it possible to choose between algorithms?
Regards
February 28, 2015 at 05:20 am - Permalink
i found out how to do it....however, using backward or forward differences solves the problem partly.....now the second derivatives seem a lot more similar but there is still a problem.....using matlab i get maximum negative values up to -3 in the second derivative, while with igor pro up to -2.....i am trying to understand why is that.
February 28, 2015 at 07:17 am - Permalink
Differentiate jack /D=dif1
SetScale/P x, 0, .1, jack
Differentiate jack /D=dif2
Display dif1, dif2
For information on X scaling, execute:
February 28, 2015 at 01:40 pm - Permalink