SwitcherCad Q

I have this small .RAW file (over 1Gbyte) and i want to do an X-Y plot of two parameters. Reading this file is fairly easy and fast, but i do not know the formatting - so i do not know how to pick out a given dataset, like V(n017) and V(n002). How can this be done?

On Nov 2, 7:27 am, Robert Baer

The file *should* start with a decent header including a description of the format used to encode the data. Why not post the first few Kb here to attempt to reverse its format ?

Are the files in the default binary format, or have you checked the "ASCII Data Files" box?

I import ASCII rawfiles into Berkeley Spice 3f4 (a few LTSpice-specific lines at the head of the file need getting rid of), and do polar plots from there.

There's an m-file for importing spice rawfiles into Matlab. Won't run in octave, even with the --braindead command line option.

There's another for octave, but it doesn't seem to parse LTSpice rawfiles properly. Tells me there are 0 variables and 0 points. Still playing with it.

I don't think you're going to have much luck trying to interpret the RAW data file format. From the manual at

LTspice compresses the raw data files as they are generated. A compressed file can be 50 times smaller than the un-compressed one. This is a lossy compression. This pane of the control panel allows you to control how lossy the compression runs.

-- Marc

On Nov 2, 9:21=A0pm, Marc Guardiani

Then set the compression ratio to zero % to get a uncompressed RAW file - will this work ?

"Robert Baer" schrieb im Newsbeitrag news:B_-dna5Oycu-PFLRnZ2dnUVZ snipped-for-privacy@posted.localnet...

Hello Robert,

If you have the waveform window active, you can simply do an export of waveforms.

File -> Export

A dialog window will pop-up. Select the waveforms you want to export.

If you already have the raw-file and want open it again, just drag it into LTspice from the Windows explorer.window.

Best regards, Helmut

If you have access to Matlab you can use the LTspice2Matlab m file to import a LTspice raw file into Matlab. See:

Howard

The files are created by switcherCad; draw any schematic (that will run) and save. Look at the .RAW file; the header has no info concerning the format or coding. The only "clues" are the names (and count) of the nodes, possible order of values per node, and terminated by "Binary:" (no quotes).

That is a thought; i did default mode (ascii header, binary data). Will see if i can try the ASCII format; file will prolly by 8 to 16 times larger or roughly(?) 32Gbytes if the OS allows such a size (forgot).

Holy S!!!!!!!! FIFTY times?? That is maybe 100Gbytes uncompressed! Even if the OS would allow a filesize like that, i would need to get a terror-bite HD to chomp on!

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If it is settable at all, a factor of ONE is the logical value; division by zero is NAN. BTW, i have seen some NaN in the binary..

Will try, but it is not the waveform, it is the data stream of one node VS another note i want to plot.

Heh... He said 'suc-seed!'

The RNG in NetHack is better than that!

You guys are seedy characters!

I am The WallRus! King of ArmageTRON Advanced!

Additive or subtractive? (same as the termination resistance question).

Robert,

Yuu will get a text file with three columns. Then use any other plot program to plot the second column versus the third column. Isn't that what you wanted to plot.

You can do an x-y plot in LTspice too. Simply chnage the x-axis to V(node2).

If you want a smaller data file, you can limit the saved data to only those two nodes with a SPICE-directive in your schematic.

.save V(node1) V(node2)

Best regards, Helmut.

But not a polar or Smith plot. Good ol' Berkeley Spice will.

Shame that.

I've got the octave input thing running properly with LTSpice ASCII rawfiles. Loads the variables into a matrix. An octave whizz (which I'm not) could probably do all sorts of clever things.

Only works with ASCII files, not binary.

OOOOooohhh!! Super! Many thanks.