gpscsv - Man Page
dump the JSON output from gpsd as CSV
Synopsis
gpscsv [-?] [--class MCLASS] [--count COUNT] [--cvt-isotime] [--debug LVL] [--device DEVICE] [--fields FIELDS] [--file FILE] [--header HEADER] [--help] [--host HOST] [--port PORT] [--seconds FIELDS] [--separator SEPARATOR] [--version] [-c MCLASS] [-D LVL] [-f FIELDS] [-h] [-n COUNT] [-V] [-x FIELDS] [host[:port[:device]]]
Description
gpscsv is a simple Python program for reading a gpsd JSON data streams and outputting them in Comma Separated Values (CSV) format. It takes input from a specified gpsd and reports to standard output. The program runs until the gpsd dies, "-n COUNT" messages are processed, "-x SECONDS" have passed, or it is interrupted by ^C or other means.
One good use of gpscsv is to create CSV files for use with the gnuplot program.
Options
The program accepts the following options:
- -?, -h, --help
Show help information and exit.
- -c MCLASS, --class MCLASS
Select the JSON class messages of type MCLASS. Default is TPV. .
- --cvt-isotime
Convert fields named "time" from ISO time to UNIX time.
- -D LVL, --debug LVL
Set debug level to LVL. Default 0. Higher arguments than 0 produce more debug output.
- --device DEVICE
The DEVICE on the gpsd to connect to. Defaults to all.
- -f FIELDS, -fields FIELDS
The FIELDS from the JSON message to dump to the output. Set FIELD to empty ('') for all fields Default varies by CLASS.
- --file FILE
Read JSON from FILE instead of from gpsd..
- --header HEADER
Set header style to HEADER. 0 for no header, 1 output fields as header, 2 send fields as a comment ('#'). Defaults to 1.
- --host HOST
Connect to the gpsd on HOST. Defaults to localhost.
- -n COUNT, --count COUNT
Exit after outputting COUNT records. Set COUNT to 0 to disable. Default is 0
- --port PORT
Use PORT to connect to gpsd. Defaults to 2947.
- --separator SEPARATOR
Use SEPARATOR as the field separator. Default separator is a comma (',').
- -V, --version
Show gpscsv version, and exit.
- -x SECONDS, --seconds SECONDS
Exit after SECONDS number of seconds have passed. Set SECONDS to 0 to disable. Default is 0
Examples
Some basic examples, do them in exact order shown:
Grab 100 samples of time,lat,lon,altHAE:
$ gpscsv -n 100 --cvt-isotime > tpv.dat
Grab 100 samples of time,epx,epy,epv,eph,sep
$ gpscsv -n 100 --cvt-isotime -f time,epx,epy,epv,eph,sep > ep.dat
Grab 100 samples of time,xdop,ydop,vdop,tdop,hdop,gdop,pdop
$ gpscsv -n 100 --cvt-isotime -c SKY > sky.dat
Grab 100 samples of time,nSat,uSat
$ gpscsv -n 100 --cvt-isotime -c SKY -f time,nSat,uSat > sat.dat
start gnuplot in interactive mode:
$ gnuplot
Some gnuplot housekeeping:
# this are csv files gnuplot> set datafile separator ',' # use the first line as title gnuplot> set key autotitle columnhead # X axis is UNIT time in seconds. gnuplot> set xdata time gnuplot> set timefmt "%s"
Now to plot time vs latitude:
gnuplot> plot 'tpv.dat' using 1:2
Then to plot longitude and altHAE, in separate plots:
gnuplot> plot 'tpv.dat' using 1:3 gnuplot> plot 'tpv.dat' using 1:4
Put both latitude and longitude on one plot:
gnuplot> set y2tics gnuplot> plot 'tpv.dat' using 1:2, '' using 1:3 axes x1y2
Plot epx, epy, epv, eph, and sep in one plot:
gnuplot> plot 'ep.dat' using 1:2, '' using 1:3, \ '' using 1:4, '' using 1:5, '' using 1:6
Plot all the DOPs on one plot:
gnuplot> plot 'sky.dat' using 1:2, '' using 1:3, '' using 1:4, \ '' using 1:5, '' using 1:6, '' using 1:7, '' using 1:8
Plot nSat and uSat together:
gnuplot> plot 'sat.dat' using 1:2, '' using 1:3
Lat/lon scatter plot:
# x is no longer time gnuplot> set xdata gnuplot> plot 'tpv.dat' using 3:2 title 'fix'
See Also
Author
Gary E. Miller <gem@rellim.com>.