FuncFit thinks complex y wave and real x wave have a different number of points
Hi all,
I'm trying to write an all-at-once fitting function for a frequency-domain measurement. I'm trying to use a 62-data-point complex y wave and a 62-data-point real-only x wave as the input, but I get an error saying that the x and y data contain a different number of points. Any ideas?
In the following code, I split up the output from the instrument (5 columns: frequency, X channel signal, error in X channel, Y channel signal, error in Y channel) into a wave for the x data (wF, the frequencies used) and the real and imaginary components of the signal (wX and wY, respectively), which get combined into a 1-dimensional complex-valued wave, wComplex. I then try to pass the complex-valued wComplex as the y data and wF as the x data for FitFunc, but it gives me the error, "error: X and Y data have different number of points."
I also wrote it to fit as the log of the function thinking it would save time, but honestly, even having 50000 simulated points in the all-at-once function is pretty fast, hence the weird shenanigans with the log and 10^x stuff.
Function SSMC_FreqFit(w0,wParam) WAVE w0,wParam Duplicate/FREE/O/R=[][0] w0, wF Duplicate/FREE/O/R=[][1] w0, wX Duplicate/FREE/O/R=[][3] w0, wY Variable NumFreqs = DimSize(w0,0) Make/C/O/N=(NumFreqs) wComplex wComplex[] = cmplx(wX[p],wY[p]) String CFitName = NameOfWave(w0) + "_CFit" Duplicate/O wComplex,$CFitName WAVE wCFit = $CFitName WAVE ParamTable WAVE ParamHold String HoldStr = num2str(ParamHold[0]) + num2str(ParamHold[1]) + num2str(ParamHold[2]) + num2str(ParamHold[3]) + num2str(ParamHold[4]) + num2str(ParamHold[5]) + num2str(ParamHold[6]) + num2str(ParamHold[7]) + num2str(ParamHold[8]) FuncFit/H=HoldStr SSMC_FreqFit_proc, ParamTable, wComplex /X=wF/D=wCFit String ParamOut = NameOfWave(w0) + "_Param" String ParamSOut = ParamOut + "_s" Duplicate/O wParam,$ParamOut WAVE W_sigma Duplicate/O W_sigma,$ParamSOut WAVE wParamOut = $ParamOut WAVE wParamSOut = $ParamSOut String OutName = NameOfWave(w0) + "_Fit" Duplicate/O w0,$OutName WAVE wOut = $OutName wOut[][0] = w0[p][0] wOut[][1] = real(wCFit[p]) wOut[][2] = 0 wOut[][3] = imag(wCFit[p]) wOut[][4] = 0 End Function SSMC_FreqFit_Proc(wcoef, yw, xw) :FitFunc WAVE wcoef WAVE/C yw WAVE xw Variable A0 = wcoef[0] Variable t0 = wcoef[1] Variable A1 = wcoef[2] Variable t1 = wcoef[3] Variable A2 = wcoef[4] Variable t2 = wcoef[5] Variable F0 = Log(wcoef[6]) Variable F1 = Log(wcoef[7]) Variable Sig = wcoef[8] Variable Res = 0.0001 Make/O/N=(F1/Res-F0/Res,5)/FREE wFit SetScale/p x F0,Res,"",wFit wFit[][0] = 10^x wFit[][1] = Sig*(A0*t0/(1+(2*pi*10^x)^2*t0^2)+A1*t1/(1+(2*pi*10^x)^2*t1^2)+A2*t2/(1+(2*pi*10^x)^2*t2^2))/(A0*t0+A1*t1+A2*t2) wFit[][2] = 0 wFit[][3] = -Sig*(A0*(2*pi*10^x)*t0^2/(1+(2*pi*10^x)^2*t0^2)+A1*(2*pi*10^x)*t1^2/(1+(2*pi*10^x)^2*t1^2)+A2*(2*pi*10^x)*t2^2/(1+(2*pi*10^x)^2*t2^2))/(A0*t0+A1*t1+A2*t2) wFit[][4] = 0 Duplicate/O/FREE/R=[][0] wFit, SimFreqs Duplicate/O/FREE/R=[][1] wFit, SimX Duplicate/O/FREE/R=[][3] wFit, SimY yw[] = cmplx(interp(xw[p],SimFreqs,SimX),interp(xw[p],SimFreqs,SimY)) End
Update: easy solution. Make the frequency wave complex also but just leave the imaginary component as 0.
wF_Complex[] = cmplx(wF[p],0)October 2, 2025 at 03:39 pm - Permalink
I think the combination of complex Y and real X should work. Could you post an experiment file? Complex fitting is pretty new and hardly used by anyone, so it hasn't had problems shaken out yet.
October 2, 2025 at 05:18 pm - Permalink