Plotting Spectrum

siddharth · Post by **siddharth** » Wed Nov 17, 2010 1:23 am

Hi Guys,
I am new to Dplot.
I would like to know if I can use the FFT function in Dplot to plot the spectrum.
My input is 2D csv file.
If yes, please let me know how to plot?

Regards
Sid

Post by **DPlotAdmin** » Wed Nov 17, 2010 10:22 am

Sorry, but you'll have to be more specific. What does your input represent? And what sort of spectrum are you looking for?

siddharth · Post by **siddharth** » Thu Nov 18, 2010 5:42 am

Hi,
Input is time domain data stored in .csv file (2 columns) .
1st column is real and 2nd column is imaginary data.
Number of samples is around 200K.

Regards
Sid

Post by **DPlotAdmin** » Thu Nov 18, 2010 10:39 am

DPlot doesn't work directly with imaginary numbers, other than temporary storage when using FFT.

What you can do, though, is first generate a third curve that contains the magnitudes of your complex numbers, with Generate>Y=f(X,Y1,Y2,...) and

Y=sqrt(Y1^2+Y2^2)

and then run the FFT on that third curve.