How can I view uncertainty values in magnitude using Python

[Rob Feldman]

I am trying to create a calibration certificate from the data collected from VNA Tools II.  I have CITI files but the uncertainty is represented as Real and Imaginary.  I would like to convert them to Magnitude (dB) and Phase (degrees) using python.

Thanks in advance for the assistance.

[Michael Wollensack METAS]

Hi,

I've you have only CITI files with real and imaginary uncertainties the conversion to mag and phase uncertainties is not ambiguous, because you don't know the correlation between real and imaginary parts.

What is your source file?

If it would be sdatb then you can load it from VNA Tools, MATLAB or Python and you can compute the magnitude and phase uncertainties.

Regards

Michael

[Rob Feldman]

I do have a sdatb file as my source.  My main goal is take the sdatb file and display the data (magnitude and phase) so that I can export to a word template. I would prefer to do that in Python if possible.  

[Michael Wollensack METAS]

Hi,

do you want to use the VNA Tools built-in IronPython script engine or do you want to use CPython?

Regards

Michael

[Michael Wollensack METAS]

Ok, the following script will help you:

import clr

clr.AddReference('System.Windows.Forms')

clr.AddReference('Metas.Vna.Tools')

from System import Math

from System.Threading import Thread

from System.Windows.Forms import MessageBox

from Metas.Vna.Tools import Script

s = Script(RootPath)

d = s.LoadSParamData(r'01_Basic_Example_N(f-m)\SOLT_01_out\DUTs\01419_Att20dB(f-m)_52371_01\01419_Att20dB(f-m)_52371_01_01.sdatb')

print(d.NFreq)

print(d.NPorts)

print(d[d.NFreq-1,1,0].Abs().Value) # |s21| of last frequency point

print(d[d.NFreq-1,1,0].Abs().StdUnc * 2) # U(|s21|) of last frequency point

print(d[d.NFreq-1,1,0].Abs().Log10().Value * 20) # |s21| of last frequency point

print(d[d.NFreq-1,1,0].Abs().Log10().StdUnc * 2 * 20) # U(|s21|) of last frequency point

print(d[d.NFreq-1,1,0].Angle().Value * 180 / Math.PI ) # angle(s21) of last frequency point

print(d[d.NFreq-1,1,0].Angle().StdUnc * 2* 180 / Math.PI) # U(angle(s21)) of last frequency point

[Rob Feldman]

Thanks, that is exactly what I needed!