I did a comparison of the time needed to load a big binary raw file (370MB) with xschem and the time needed to do the same thing with a python package I found, called spyci. This package only reads ascii files so I prepared an equivalent ascii raw file (1GB, ascii is less size efficient than binary). The result is that xschem reads the file in 0.9 seconds and takes slightly more RAM (384MB) than the size of the raw file. This is close to the time taken by ngspice itself to load the raw file (try

load poweramp.raw

at the ngspice prompt) The python package took more than 1' 40" to load the file and RAM utilization grew up close to 7.8GB while reading the file and shrunk down to 1.5GB after finishing the load operation. If you know other packages that read raw files let me know I will do more tests. So far IMHO the best way to examine a raw file and save selected data for post processing is ngspice itself:

ngspice 232 -> load poweramp.raw
ngspice 233 -> set nobreak
ngspice 234 -> print v(outp) v(refp) > xxx
ngspice 235 -> exit

The

xxx

file looks like:

** sch_path: /home/schippes/xschem-repo/trunk/xschem_library/examples/poweramp.sch
Transient Analysis  Sun Apr 21 00:11:46  2024
--------------------------------------------------------------------------------
Index   v(outp)         v(refp)
--------------------------------------------------------------------------------
0       4.185864e-11    4.083358e-09
1       4.569094e-11    4.452056e-09
2       5.402568e-11    5.234371e-09
3       7.516473e-11    7.009691e-09
4       1.399077e-10    1.107425e-08
...
...

An even better way to export data with ngspice is `wrdata`:

ngspice 236 -> load poweramp.raw
ngspice 237 -> set wr_singlescale
ngspice 238 -> set wr_vecnames
ngspice 239 -> wrdata xxx v(outp) i(vcurrvpp) v(refp)
ngspice 240 -> exit

and the xxx file is clean with no junk comments, only the data. (credits to @Tim Edwards for wrdata method) the

xxx

file:

time            v(outp)         i(vcurrvpp)     v(refp)
 2.00000000e-09  4.18586447e-11  9.99800050e-04  4.08335771e-09 
 2.16802293e-09  4.56909362e-11  1.08379330e-03  4.45205625e-09 
 2.50406879e-09  5.40256799e-11  1.25177699e-03  5.23437090e-09
 3.17616050e-09  7.51647284e-11  1.58772743e-03  7.00969105e-09
 4.52034393e-09  1.39907685e-10  2.25956059e-03  1.10742512e-08
 7.20871079e-09  3.95715337e-10  3.60295603e-03  2.03744789e-08
...
...