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Fast Import of Compressed Binary .RAW Files Created with LTspice Circuit Simulator



22 Mar 2009 (Updated )

Loads .raw simulation files created with LTspice (a free circuit simulation tool).

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LTSPICE2MATLAB imports an LTspice IV .RAW waveform file containing data from a Transient Analysis (.tran) or AC Analysis (.ac) simulation, and converts voltages and currents vs. time (or frequency) into a Matlab data structure. This function can read compressed binary, uncompressed binary, and ASCII file formats. In the case of compressed binary, the data is automatically uncompressed using fast quadratic point insertion. This function handles very large binary simulation files efficiently, and has an option to load only a subset of a file's waveforms to reduce memory consumption. Type >> help LTspice2Matlab for details.

Use LTSPICE2MATLAB to import LTspice waveforms for additional analysis in Matlab, or for comparison with measured data. LTspice2Matlab has been tested with LTspice IV version 4.01p, and Matlab versions 6.1 and 7.5., and regression testing has been used to expose the function to a wide range of LTspice settings.

Note: LTspice IV is a Spice III simulator and schematic capture tool freely avaliable for download at www.linear.com/designtools/software. It is optimized for simulation of switching regulators, but can simulate many other types of circuits as well and comes with a variety of component models.


This file inspired Run Ngspice Simulation And Import Rawfile.

MATLAB release MATLAB 6.1 (R12.1)
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Comments and Ratings (14)
26 Jul 2015 Sidney

Sidney (view profile)

I am trying to run the LTSpice2Matlab code provided here but I am getting this error

>> LTspice2Matlab
Error using LTspice2Matlab (line 130)
LTspice2Matlab takes 1, 2, or 3 input parameters. Type "help LTspice2Matlab" for details

Please can someone advice me on how to solve this problem?

Kind regards


23 Dec 2013 Patrick Vogelsang

Hi Paul this is very usefull. Thanks! I often work with parameter stepping. I observed that LTspice2matlab does not cover this feature. It outputs all steps sequencially without notifying that it is stepped data and providing info about about runs. This would a be nice feature for the next version.

29 Jun 2013 Dick Benson

Dick Benson (view profile)

Sweet! Thanks!

13 May 2013 Raj Sodhi

Raj Sodhi (view profile)

This is fantastic! I struggled with Helmut's ltsputil.exe program for a while, intending to bring the final results into Matlab and this program does all that in 1 step.

11 Feb 2013 Richard  
06 Nov 2012 Alan

Alan (view profile)

This failed for me

Error using LTspice2Matlab (line 212)
Format error in LTspice file "/Users/acurtis/Desktop/test.raw" ... Wrong number of
columns in the variable define section

I created the raw file from an example circuit netlist I got from


I chose the "RC filter AC response" and copied the netlist to a file. I ran ngspice with the command

ngspice --batch --rawfile="test.raw" "rc.net"

and then in MATLAB


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21 May 2012 Daniel

Daniel (view profile)


Very useful function. However, i detect some "NaN" (not a number) conversions in MATLAB which are not a problem to plot data but it is for making calculations. Does anybody know how to deal with them without increasing the computation time.

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18 Dec 2011 sergi

sergi (view profile)

09 Mar 2011 Mickael Lefebvre


Thanks very much for this function, I managed to get it to work with Octave (3.2.0 on Win7). Are you interested in the modifications?
Thanks again

20 Apr 2009 Lian

Lian (view profile)

Hello, anybody can upload or post the commands in matlab to plot the "RAW DATA" structure into a Figure, thank you in advance.

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20 Apr 2009 Lian

Lian (view profile)

this file is very useful as the analysis function in LTspice is limited in some extend.

20 Apr 2009 Howard

Howard (view profile)

Update, my previous comment was caused by an error I made when using LTspice2Matlab.m Once I enclosed the path and file name in single quotes the LTspice2Matlab.m file program ran successfully. I had forgotten strings have to be enclosed in single quotes in Matlab.


11 Apr 2009 Howard

Howard (view profile)

I have tried using LTspice2Matlab.m with the 1010.asc and pll2.asc examples that come with LTspice and both produce an "unexpected Matlab operator error. This is with version 4.01p of Ltspice and versions 7.5 and 7.7 of Matlab. I also noticed Matlab's Current Directory function doesn't work with LTspice2Matlab.m

I assume others have had better results but so far I have been unable to load a raw LTspice file.

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23 Mar 2009 Heinrich Acker

Thanks alot for this file. It works as expected, much better than my own import function, which requires to set LTspice to ASCII output. But ASCII is not the preferred output, one usually wants to use LTspice with its .RAW format.

The source of this function uses long, descriptive varnames and has a very good help section at the beginning.

Btw, I tested with Matlab 7.5 (R2007b) and LTspice III (2.16z), and everything worked well.

It may sound pedantic, but there are only few comments after the help section and mlint gives quite some warnings on this file.

It would be nice to see this very useful program extented to other simulation types than .TRAN.

28 Mar 2009 1.1

Added support for AC Analysis (.ac) simulation files.

30 Mar 2009 1.2

Added support for AC Analysis (.ac) simulations

26 Apr 2009 1.3

Updated help section at beginning of file

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