Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or width in UNIT (upper case modifier).
UNIT is cm, inch, or m, depending on the MEASURE_UNIT setting in .gmtdefaults4, but this can be
overridden on the command line by appending c, i, or m to the scale/width value.
When central meridian is optional, default is center of longitude range on -R option.
Default standard parallel is the equator.
For map height, max dimension, or min dimension, append h, +, or - to the width,
More details can be found in the psbasemap man pages.
-Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area)
-Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
|-R||xmin, xmax, ymin, and ymax specify the Region of interest. For geographic regions, these limits correspond to west, east, south, and north and you may specify them in decimal degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and upper right map coordinates are given instead of w/e/s/n. The two shorthands -Rg and -Rd stand for global domain (0/360 and -180/+180 in longitude respectively, with -90/+90 in latitude). Alternatively, specify the name of an existing grid file and the -R settings (and grid spacing, if applicable) are copied from the grid. For calendar time coordinates you may either give (a) relative time (relative to the selected TIME_EPOCH and in the selected TIME_UNIT; append t to -JX|x), or (b) absolute time of the form [date]T[clock] (append T to -JX|x). At least one of date and clock must be present; the T is always required. The date string must be of the form [-]yyyy[-mm[-dd]] (Gregorian calendar) or yyyy[-Www[-d]] (ISO week calendar), while the clock string must be of the form hh:mm:ss[.xxx]. The use of delimiters and their type and positions must be exactly as indicated (however, input, output and plot formats are customizable; see gmtdefaults).|
-A Give an audible signal each time the digitizer mouse/puck is clicked [Default is silent]. -C Specify the device (port) to read from [Default is /dev/ttyS0]. -D Only output a point if it is further than limit units from the previous point. Append c, i, m, p for cm, inch, meter, or point, respectively [Default is no limit]. -F Force the program to ask for 4 arbitrary calibration points [Default is to use the 4 corners of the map, if possible]. -H This option allows you to write out any number of header records to the beginning of the output file. Each record will automatically start with a #-character to indicate comment. Headers are not written if multiple output files are selected with -N -m. -L Set the digitizer table resolution in lines per inch . -N Set name for output file(s). If a regular filename is given, then all digitized data will be written to that file. If the file contains a C-format for an integer (i.e., %d) then the file is used as a format statement to create unique filenames based on the current segment number (e.g., line_%d.d will yield files line_0.d, line_1.d, etc). By default, all output is written to stdout. Multiple segment files requires specifying the -m option. -S Suppress points that fall outside the specified map region [Default outputs all points]. -V Selects verbose mode, which will send progress reports to stderr [Default runs "silently"]. The program will also duplicate data output to stderr for monitoring. -Z Append v to prompt for a z-value and output it as a third data column. Append k to output the button key as the final data column. Both -Zk and -Zv can be specified. [Default is just 2 column x,y output]. -bo Selects binary output. Append s for single precision [Default is d (double)]. Uppercase S or D will force byte-swapping. Optionally, append ncol, the number of desired columns in your binary output file. -m Multiple segment file(s). Segments are separated by a special record. For ASCII files the first character must be flag [Default is >]. For binary files all fields must be NaN and -b must set the number of output columns explicitly. By default the -m setting applies to both input and output. Use -mi and -mo to give separate settings to input and output.
To digitize lines from a mercator map made for a given region, and save each line segment in individual files called segment_000.xy, segment_001.xy etc, try
gmtdigitize -R 20/50/12/25 -Jm 1:1 -m -N segment_%3.3d.xy
To digitize seismically defined interfaces from a multichannel seismic section, with horizontal distances from 130 to 970, and vertical times from 0 to 10 seconds, write out the button code, and save all line segment to a single multisegment file, and beep at each click, try
gmtdigitize -R 130/970/0/10 -Jx 1/-1 -m -A -Z > interfaces.d
This applies to the Calcomp DrawingBoard III hooked up to a RedHat Linux workstation. We use /dev/ttyS0 as the serial port and change permissions so that it is world read/write-able. Then, stty -F /dev/ttyS0 evenp will set the terminal settings, which can be checked with stty -F /dev/ttyS0 -a. Setup of digitizer: We use the CalComp 2000 ASCII (Save 3) setup, which has:
Baud Rate: 9600
Data Bits: 7
Data Rate: 125 pps
Resolution: 200 lpi
Output Format: Format 0
Emulation: CalComp 2000 ASCII
(A)We need to make a slight modification to the Preset No 3 settings: (1) 2450 LPI instead of 200, and (2) None instead of yes for added CR. These modifications can be changed and saved to Preset 3 on the digitizer but a power outage may reset in back to the factory defaults, necessitating a manual reset of those two settings. (B) Setup tty port. stty -F /dev/ttyS0 evenp (C) Run gmtdigitize. Map scale does not matter; it is computed from the region and plot size.
|GMT 4.5.14||GMTDIGITIZE (1)||1 Nov 2015|