Japanese edition is here.

How to convert the polar text output of LTspice XVII's AC analysis to CSV or Tab delimited text

LTspice's polar: (db,deg) format uses ° (degree, 0xb0), a 1-byte character in ISO/IEC 8859-1. This makes it difficult to handle text data in multi-byte environments such as Japanese due to garbled characters.

So I wrote a shell script to convert the data to CSV or Tab delimited text so that it can be easily handled by Microsoft Excel or gnuplot. It can be used in environments where sed and bash are available.

When the script name is "polar2csv", it converts the LTspice polar: (db,deg) format to CSV and outputs it to the standard output. If the script name is something other than polar2csv (e.g. polar2tab), it will convert the data to Tab-delimited text and output it to the standard output.

polar2csv / polar2txt (shell script)

#!/bin/sh # # polar2csv - Polar: (db,deg) format of the LTspice XVII to CSV conversion. # # Usage # polar2csv input_file # # Example # polar2csv input_file.txt > output_file.csv # # You must set LC_ALL=C to remove the single byte degree charactor (0xb0) # used in the export text format of Polar: (dB,deg) of the AC simulation # results of the LTspice XVII. # In bash, $'string' causes "ANSI-C expansion". And that is what most of # us expect when we use things like \t, \r, \n, etc. # c.f. www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html # export LC_ALL=C if [ $# -ne 1 ]; then echo "${0##*/} - Polar: (db,deg) format of the LTspice XVII to CSV conversion." echo "Usage : ${0##*/} input_file" exit; fi if [ "${0##*/}" = "polar2csv" ]; then sed < $1 -e 's/^Freq/#Freq/' -e 's/[(,)]//g' -e 's/\xb0//g' -e $'s/\t/, /g' -e $'s/dB/, /g' else sed < $1 -e 's/^Freq/#Freq/' -e 's/[(,)]//g' -e 's/\xb0//g' -e $'s/dB/\t/g' fi #EOF

See also

• LTspice — Using Manufacturer's Libraries（Low-noise pre-regulator for LT6657A）
• LTspice — group-delay simulation（single MOS-FET 3rd-order LPF)
• LTspice — group-delay simulation (800 Hz, Linear-phase, 3rd-order pair BPF）
• LTspice — Frequency response simulation (4 kHz, Fliege-type BEF）
• LTspice — Using parameter sweep (audio band-pass filter)
• LTspice — Using function and formula in a schematic (tapped-capacitor matching)
• LTspice — Using Fourier analysis (Current feedback, four biplar-transistor amplifier)
• LTspice — Precise FFT analysis (Ultra low distortin pre-amplifier)
• LTspice — Fourier analysis of the differential signals (Multiple-feedback differential-output amplifier）
• LTspice — How to covert Polar (db,deg) format text to CSV
• LTspice — Changing the pulse width of a signal source (changing the pulse width of a signal source)

External link

• LTspice