Is there an open source waveforms viewer for analog signal ?

What exactly are you using it for?

@Bradley Moon to my knowledge here is a list of analog viewers that work for analog simulations. these are: • gaw • ngspice internal plotting ability • BeSpice Wave from Analog flavor (this is a commercial product but there is a 1 year renewable evaluation license) • Xschem function. • I think there are also python libraries for reading and plotting simulation data and doing complex calculations on these, but i have never tried.

@Bradley Moon for tansient analysis of some signals and calculate some data

@Amr_Tawfik read the README.md file, it is a known issue and can be easily fixed.

you can read .raw file using python for analysis and processing

@Ahmed Reda this link doesn't work from MC presentation