gmtconvert
gmtconvert - Convert, Paste, and/or Extract columns from data tables
Synopsis
gmtconvert [ table ] [ -A ] [ -D[template] ]
[ -E[f|l|mstride] ] [ -L ]
[ -I[tsr] ] [ -Q[~]*selection* ]
[ -S[~]“search string” |
-S[~]/regexp/[i] ]
[ -T ]
[ -V[level] ]
[ -acol=name[...] ]
[ -b[i|o][ncol][type][w][+L|+B] ]
[ -f[i|o]colinfo ]
[ -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] ]
[ -h[i|o][n][+c][+d][+rremark][+rtitle] ]
[ -icols[l][sscale][ooffset][,...] ]
[ -ocols[,...] ]
[ -s[cols][a|r] ]
[ -:[i|o] ]
Note: No space is allowed between the option flag and the associated arguments.
Description
gmtconvert reads its standard input [or input files] and writes out
the desired information to standard output. It can do a combination of
seven tasks: (1) convert between binary and ASCII data tables, (2) paste
corresponding records from multiple files horizontally into a single
file, (3) extract a subset of the available columns, (4) only extract
segments whose header record matches a text pattern search, (5) only
list segment headers and no data records, (6) extract first and/or last
data record for each segment, and (7) reverse the order
of items on output. Input (and hence output) may have multiple
sub-headers, and ASCII tables may have regular headers as well.
Optional Arguments
- table
- One or more ASCII (or binary, see -bi[ncols][type]) data
table file(s) holding a number of data columns. If no tables are given
then we read from standard input.
- -A
- The records from the input files should be pasted horizontally, not
appended vertically [Default]. All files must have the same number
of segments and number of rows per segment. Note for binary input,
all the files you want to paste must have the same number of columns
(as set with -bi); ascii tables can have different number of columns.
- -D[template]
- For multiple segment data, dump each segment to a separate output
file [Default writes a multiple segment file to stdout]. Append a
format template for the individual file names; this template
must contain a C format specifier that can format an integer
argument (the running segment number across all tables); this is
usually %d but could be %08d which gives leading zeros, etc.
[Default is gmtconvert_segment_%d.{txt|bin}, depending on
-bo]. Alternatively, give a template with
two C format specifiers and we will supply the table number and the
segment number within the table to build the file name.
- -E[f|l|mstride]
- Only extract the first and last record for each segment of interest
[Default extracts all records]. Optionally, append f or l to
only extract the first or last record of each segment, respectively.
Alternatively, append mstride to extract only one out of stride records.
- -I
- Invert the order of items, i.e., output the items in reverse order,
starting with the last and ending up with the first item [Default
keeps original order]. Append up to three items that should be
reversed: t will reverse the order of tables, s will reverse
the order of segments within each table, and r will reverse the
order of records within each segment [Default].
- -L
- Only output a listing of all segment header records and no data
records (requires ASCII data).
- -Q[~]*selection*
- Only write segments whose number is included in selection and skip
all others. Cannot be used with -S. The selection syntax is
range*[,*range,...] where each range of items is either a single
segment number, a range of segment numbers start-stop, or a range with
stepped increments given via start:step:stop. A leading ~ will
invert the selection and write all segments but the ones listed. Instead
of a list of ranges, use +ffile to supply a file list with one
range per line.
- -S[~]“search string” or -S[~]/regexp/[i]
- Only output those segments whose header record contains the
specified text string. To reverse the search, i.e., to output
segments whose headers do not contain the specified pattern, use
-S~. Should your pattern happen to start with ~ you need to
escape this character with a backslash [Default output all
segments]. Cannot be used with -Q. For matching segments based
on aspatial values (via OGR/GMT format), give the search string as
varname=value and we will compare value against the value
of varname for each segment. Note: If the features are polygons
then a match of a particular polygon perimeter also means that any
associated polygon holes will also be matched. For matching segment
headers against extended regular expressions enclose the expression
in slashes. Append i for caseless matching.
For a list of such patterns, give +ffile with one pattern per line.
To give a single pattern starting with +f, escape it with a backslash.
- -T
- Suppress the writing of segment headers on output.
- -V[level] (more ...)
- Select verbosity level [c].
- -acol=name[...] (more ...)
- Set aspatial column associations col=name.
- -bi[ncols][type] (more ...)
- Select binary input.
- -bo[ncols][type] (more ...)
- Select binary output. [Default is same as input].
- -f[i|o]colinfo (more ...)
- Specify data types of input and/or output columns.
- -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] (more ...)
- Determine data gaps and line breaks.
- -h[i|o][n][+c][+d][+rremark][+rtitle] (more ...)
- Skip or produce header record(s).
- -icols[l][sscale][ooffset][,...] (more ...)
- Select input columns (0 is first column).
- -ocols[,...] (more ...)
- Select output columns (0 is first column).
- -s[cols][a|r] (more ...)
- Set handling of NaN records.
- -:[i|o] (more ...)
- Swap 1st and 2nd column on input and/or output.
- -^ or just -
- Print a short message about the syntax of the command, then exits (NOTE: on Windows use just -).
- -+ or just +
- Print an extensive usage (help) message, including the explanation of
any module-specific option (but not the GMT common options), then exits.
- -? or no arguments
- Print a complete usage (help) message, including the explanation of
options, then exits.
- --version
- Print GMT version and exit.
- --show-datadir
- Print full path to GMT share directory and exit.
Examples
To convert the binary file test.b (single precision) with 4 columns to ASCII:
gmt gmtconvert test.b -bi4f > test.dat
To convert the multiple segment ASCII table test.d to a double precision binary file:
gmt gmtconvert test.d -bo > test.b
You have an ASCII table with 6 columns and you want to plot column 5 versus column 0. Try
gmt gmtconvert table.d -o5,0 | psxy ...
If the file instead is the binary file results.b which has 9
single-precision values per record, we extract the last column and
columns 4-6 and write ASCII with the command
gmt gmtconvert results.b -o8,4-6 -bi9s | psxy ...
You want to plot the 2nd column of a 2-column file left.d versus the
first column of a file right.d:
gmt gmtconvert left.d right.d -A -o1,2 | psxy ...
To extract all segments in the file big_file.d whose headers contain
the string “RIDGE AXIS”, try
gmt gmtconvert big_file.d -S"RIDGE AXIS" > subset.d
To invert the selection of segments whose headers begin with “profile ”
followed by an integer number and any letter between “g” and “l”, try
gmt gmtconvert -S~"/^profile [0-9]+[g-l]$/"
To reverse the order of segments in a file without reversing the order
of records within each segment, try
gmt gmtconvert lots_of_segments.txt -Is > last_segment_first.txt
To extract segments 20 to 40 in steps of 2, plus segment 0 in a file, try
gmt gmtconvert lots_of_segments.txt -Q0,20:2:40 > my_segments.txt
To extract the attribute ELEVATION from an ogr gmt file like this
# @VGMT1.0 @GPOINT
...
# @NELEVATION|DISPX|DISPY
# @Tdouble|double|double
# FEATURE_DATA
# @D4.945000|-106500.00000000|-32700.00000000
-9.36890245902635 39.367156766570389
do
gmt gmtconvert file.gmt -a2=ELEVATION > xyz.dat
or just
gmt gmtconvert file.gmt -aELEVATION > xyz.dat