gmt.conf(5) GMT gmt.conf(5)
NAME
gmt.conf - Configuration for GMT
DESCRIPTION
The following is a list of the parameters that are user-definable in
GMT. The parameter names are always given in UPPER CASE. The parameter
values are case-insensitive unless otherwise noted. The system defaults
are given in brackets [ for SI (and US) ]. Those marked * can be set on
the command line as well (the corresponding option is given in paren-
theses). Note that default distances and lengths below are given in
both cm or inch; the chosen default depends on your choice of default
unit (see PROJ_LENGTH_UNIT). You can explicitly specify the unit used
for distances and lengths by appending c (cm), i (inch), or p (points).
When no unit is indicated the value will be assumed to be in the unit
set by PROJ_LENGTH_UNIT. Several parameters take only true or false.
Finally, most of these parameters can be changed on-the-fly via the
--PARAMETER=VALUE option to any GMT program. However, a few are static
and are only read via the gmt.conf file; these are labeled (static).
COMMON SPECIFICATIONS
The full explanation for how to specify pens, pattern fills, colors,
and fonts can be found in the gmt man page.
+---------------------------+---------+
|THEMATIC SUB-SECTIONS | prefix |
+---------------------------+---------+
|COLOR Parameters | COLOR_ |
+---------------------------+---------+
|DIR Parameters | DIR_ |
+---------------------------+---------+
|FONT Parameters | FONT_ |
+---------------------------+---------+
|FORMAT Parameters | FORMAT_ |
+---------------------------+---------+
|GMT Miscellaneous Parame- | GMT_ |
|ters | |
+---------------------------+---------+
|I/O Parameters | IO_ |
+---------------------------+---------+
|MAP Parameters | MAP_ |
+---------------------------+---------+
|Projection Parameters | PROJ_ |
+---------------------------+---------+
|PostScript Parameters | PS_ |
+---------------------------+---------+
|Calendar/Time Parameters | TIME_ |
+---------------------------+---------+
COLOR_BACKGROUND
Color used for the background of images (i.e., when z < lowest
color table entry) [black].
COLOR_FOREGROUND
Color used for the foreground of images (i.e., when z > highest
color table entry) [white].
COLOR_HSV_MAX_S
Maximum saturation (0-1) assigned for most positive intensity
value [0.1].
COLOR_HSV_MIN_S
Minimum saturation (0-1) assigned for most negative intensity
value [1.0].
COLOR_HSV_MAX_V
Maximum value (0-1) assigned for most positive intensity value
[1.0].
COLOR_HSV_MIN_V
Minimum value (0-1) assigned for most negative intensity value
[0.3].
COLOR_MODEL
Selects in which color space a CPT should be interpolated. By
default, color interpolation takes place directly on the RGB
values which can produce some unexpected hues, whereas interpo-
lation directly on the HSV values better preserves those hues.
The choices are: none (default: use whatever the COLOR_MODEL
setting in the CPT demands), rgb (force interpolation in RGB),
hsv (force interpolation in HSV), cmyk (assumes colors are in
CMYK but interpolates in RGB).
COLOR_NAN
Color used for the non-defined areas of images (i.e., where z ==
NaN) [127.5].
DIR_CACHE
Cache directory where to save files downloaded when using exter-
nal URL addresses or the files called earth_relief_res.grd or
filenames starting in @ (e.g., @hotspots.txt)
DIR_DATA
Session data dir. Overrides the value of the environment vari-
able $GMT_DATADIR (see Directory parameters in the CookBook).
DIR_DCW
Path to optional Digital Chart of the World polygon files.
DIR_GSHHG
Path to GSHHG files. Defaults to $GMT_SHAREDIR/coast if empty.
FONT Sets the default for all fonts, except FONT_LOGO. This setting
is not included in the gmt.conf file.
FONT_ANNOT
Sets both FONT_ANNOT_PRIMARY and FONT_ANNOT_SECONDARY to the
value specified. This setting is not included in the gmt.conf
file.
FONT_ANNOT_PRIMARY
Font used for primary annotations, etc. [12p,Helvetica,black].
When + is prepended, scale fonts, offsets and tick-lengths rela-
tive to FONT_ANNOT_PRIMARY.
FONT_ANNOT_SECONDARY
Font to use for time axis secondary annotations [14p,Hel-
vetica,black].
FONT_LABEL
Font to use when plotting labels below axes [16p,Hel-
vetica,black].
FONT_LOGO
Font to use for text plotted as part of the GMT time logo
[8p,Helvetica,black].
FONT_TITLE
Font to use when plotting titles over graphs [24p,Hel-
vetica,black].
FORMAT_CLOCK_IN
Formatting template that indicates how an input clock string is
formatted. This template is then used to guide the reading of
clock strings in data fields. To properly decode 12-hour clocks,
append am or pm (or upper case) to match your data records. As
examples, try hh:mm, hh:mm:ssAM, etc. [hh:mm:ss].
FORMAT_CLOCK_MAP
Formatting template that indicates how an output clock string is
to be plotted. This template is then used to guide the format-
ting of clock strings in plot annotations. See FORMAT_CLOCK_OUT
for details. [hh:mm:ss].
FORMAT_CLOCK_OUT
Formatting template that indicates how an output clock string is
to be formatted. This template is then used to guide the writing
of clock strings in data fields. To use a floating point format
for the smallest unit (e.g., seconds), append .xxx, where the
number of x indicates the desired precision. If no floating
point is indicated then the smallest specified unit will be
rounded off to nearest integer. For 12-hour clocks, append am,
AM, a.m., or A.M. (GMT will replace a|A with p|P for pm). If
your template starts with a leading hyphen (-) then each integer
item (y,m,d) will be printed without leading zeros (default uses
fixed width formats). As examples, try hh:mm, hh.mm.ss,
hh:mm:ss.xxxx, hha.m., etc. [hh:mm:ss]. If the format is simply
- then no clock is output and the ISO T divider between date and
clock is omitted.
FORMAT_DATE_IN
Formatting template that indicates how an input date string is
formatted. This template is then used to guide the reading of
date strings in data fields. You may specify either Gregorian
calendar format or ISO week calendar format. Gregorian calendar:
Use any combination of yyyy (or yy for 2-digit years; if so see
TIME_Y2K_OFFSET_YEAR), mm (or o for abbreviated month name in
the current time language), and dd, with or without delimiters.
For day-of-year data, use jjj instead of mm and/or dd. Examples
can be ddmmyyyy, yy-mm-dd, dd-o-yyyy, yyyy/dd/mm, yyyy-jjj, etc.
ISO Calendar: Expected template is yyyy[-]W[-]ww[-]d, where ww
is ISO week and d is ISO week day. Either template must be con-
sistent, e.g., you cannot specify months if you do not specify
years. Examples are yyyyWwwd, yyyy-Www, etc. [yyyy-mm-dd].
FORMAT_DATE_MAP
Formatting template that indicates how an output date string is
to be plotted. This template is then used to guide the plotting
of date strings in data fields. See FORMAT_DATE_OUT for details.
In addition, you may use a single o instead of mm (to plot month
name) and u instead of W[-]ww to plot aWeek ##a. Both of these
text strings will be affected by the GMT_LANGUAGE, FOR-
MAT_TIME_PRIMARY_MAP and FORMAT_TIME_SECONDARY_MAP setting.
[yyyy-mm-dd].
FORMAT_DATE_OUT
Formatting template that indicates how an output date string is
to be formatted. This template is then used to guide the writing
of date strings in data fields. You may specify either Gregorian
calendar format or ISO week calendar format. Gregorian calendar:
Use any combination of yyyy (or yy for 2-digit years; if so see
TIME_Y2K_OFFSET_YEAR), mm (or o for abbreviated month name in
the current time language), and dd, with or without delimiters.
For day-of-year data, use jjj instead of mm and/or dd. As exam-
ples, try yy/mm/dd, yyyy=jjj, dd-o-yyyy, dd-mm-yy, yy-mm, etc.
ISO Calendar: Expected template is yyyy[-]W[-]ww[-]d, where ww
is ISO week and d is ISO week day. Either template must be con-
sistent, e.g., you cannot specify months if you do not specify
years. As examples, try yyyyWww, yy-W-ww-d, etc. If your tem-
plate starts with a leading hyphen (-) then each integer item
(y,m,d) will be printed without leading zeros (default uses
fixed width formats) [yyyy-mm-dd]. If the format is simply -
then no date is output and the ISO T divider between date and
clock is omitted.
FORMAT_GEO_MAP
Formatting template that indicates how an output geographical
coordinate is to be plotted. This template is then used to guide
the plotting of geographical coordinates in data fields. See
FORMAT_GEO_OUT for details. In addition, you can append A which
plots the absolute value of the coordinate. The default is
ddd:mm:ss. Not all items may be plotted as this depends on the
annotation interval.
FORMAT_GEO_OUT
Formatting template that indicates how an output geographical
coordinate is to be formatted. This template is then used to
guide the writing of geographical coordinates in data fields.
The template is in general of the form [+|-]D or
[+|-]ddd[:mm[:ss]][.xxx][F]. By default, longitudes will be
reported in the range [-180,180]. The various terms have the
following purpose:
+D Output longitude in the range [0,360]
-D Output longitude in the range [-360,0]
D Use FORMAT_FLOAT_OUT for floating point degrees.
ddd Fixed format integer degrees
: delimiter used
mm Fixed format integer arc minutes
ss Fixed format integer arc seconds
.xxx Floating fraction of previous integer field, fixed width.
F Encode sign using WESN suffix
G Same as F but with a leading space before suffix
The default is D.
FORMAT_FLOAT_MAP
Format (C language printf syntax) to be used when plotting dou-
ble precision floating point numbers along plot frames and con-
tours. For geographic coordinates, see FORMAT_GEO_MAP.
[%.12lg].
FORMAT_FLOAT_OUT
Format (C language printf syntax) to be used when printing dou-
ble precision floating point numbers to output files. For geo-
graphic coordinates, see FORMAT_GEO_OUT. [%.12lg]. To give some
columns a separate format, supply one or more comma-separated
cols:format specifications, where cols can be specific columns
(e.g., 5 for 6th since 0 is the first) or a range of columns
(e.g., 3-7). The last specification without column information
will override the format for all other columns. Alternatively,
you can list N space-separated formats and these apply to the
first N columns.
FORMAT_TIME_MAP
Sets both FORMAT_TIME_PRIMARY_MAP and FORMAT_TIME_SECONDARY_MAP
to the value specified. This setting is not included in the
gmt.conf file.
FORMAT_TIME_PRIMARY_MAP
Controls how primary month-, week-, and weekday-names are for-
matted. Choose among full, abbreviated, and character. If the
leading f, a, or c are replaced with F, A, and C the entire
annotation will be in upper case [full].
FORMAT_TIME_SECONDARY_MAP
Controls how secondary month-, week-, and weekday-names are for-
matted. Choose among full, abbreviated, and character. If the
leading f, a, or c are replaced with F, A, and C the entire
annotation will be in upper case [full].
FORMAT_TIME_STAMP
Defines the format of the time information in the UNIX time
stamp. This format is parsed by the C function strftime, so
that virtually any text can be used (even not containing any
time information) [%Y %b %d %H:%M:%S].
GMT_COMPATIBILITY
Determines if this GMT version should be able to parse com-
mand-line options for a prior major release. Specify either 4
or 5. If 4 is set we will parse obsolete GMT 4 options and issue
warnings; if 5 is set then parsing GMT 4 only syntax will result
in errors [4].
GMT_EXPORT_TYPE
This setting is only used by external interfaces and controls
the data type used for table entries. Choose from double, sin-
gle, [u]long, [u]int, [u]short, and [u]char [double].
GMT_EXTRAPOLATE_VAL
Determines what to do if extrapolating beyond the data domain.
Choose among aNaNa, aextrapa or aextrapval,vala (without
quotes). In the first case return NaN for any element of x that
is outside range [Default]. Second case lets the selected algo-
rithm compute the extrapolation values. Third case sets the
extrapolation values to the constant value passed in avala (this
value must off course be numeric).
GMT_CUSTOM_LIBS
Comma-separated list of GMT-compliant shared libraries that
extend the capability of GMT with additional custom modules
[none]. Alternatively, provide a directory name, that MUST end
with a slash (or back slash), to use all shared libraries in
that directory. On Windows, if the dir name is made up only of a
single slash (a/a) search inside a subdirectory called
agmt_pluginsa of the directory that contains the agmta exe-
cutable. See the API documentation for how to build your own
shared modules.
GMT_FFT
Determines which Fast Fourier Transform (FFT) should be used
among those that have been configured during installation.
Choose from auto (pick the most suitable for the task among
available algorithms), fftw[,planner_flag] (The Fastest Fourier
Transform in the West), accelerate (Use the Accelerate Framework
under OS X; Note, that the number of samples to be processed
must be a base 2 exponent), kiss, (Kiss FFT), brenner Brenner
Legacy FFT [auto]. FFTW can alearna how to optimally compute
Fourier transforms on the current hardware and OS by computing
several FFTs and measuring their execution time. This so gained
aWisdoma will be stored in and reloaded from the file fftw_wis-
dom_<hostname> in $GMT_USERDIR or, if $GMT_USERDIR is not
writable, in the current directory. To use this feature append
planner_flag, which can be one of measure, patient, and exhaus-
tive; see FFTW reference for details. The default FFTW planner
flag is estimate, i.e., pick a (probably sub-optimal) plan
quickly. Note: if you need a single transform of a given size
only, the one-time cost of the smart planner becomes signifi-
cant. In that case, stick to the default planner, estimate,
based on heuristics.
GMT_HISTORY
Passes the history of past common command options via the
gmt.history file. The different values for this setting are:
true, readonly, false, to either read and write to the gmt.his-
tory file, only read, or not use the file at all [true].
GMT_INTERPOLANT
Determines if linear (linear), Akimaas spline (akima), natural
cubic spline (cubic) or no interpolation (none) should be used
for 1-D interpolations in various programs [akima].
GMT_LANGUAGE
Language to use when plotting calendar and map items such as
months and days, map annotations and cardinal points. Select
from:
o CN1 Simplified Chinese
o CN2 Traditional Chinese
o DE German
o DK Danish
o EH Basque
o ES Spanish
o FI Finnish
o FR French
o GR Greek
o HI Hawaiian
o HU Hungarian
o IE Irish
o IL Hebrew
o IS Icelandic
o IT Italian
o JP Japanese
o KR Korean
o NL Dutch
o NO Norwegian
o PL Polish
o PT Portuguese
o RU Russian
o SE Swedish
o SG Scottish Gaelic
o TO Tongan
o TR Turkish
o UK British English
o US US English
If your language is not supported, please examine the
$GMT_SHAREDIR/localization/gmt_us.locale file and make a similar
file. Please submit it to the GMT Developers for official inclu-
sion. Custom language files can be placed in directories
$GMT_SHAREDIR/localization or ~/.gmt. Note: Some of these lan-
guages may require you to also change the PS_CHAR_ENCODING set-
ting.
GMT_TRIANGULATE
Determines if we use the Watson [Default] or Shewchuk algorithm
(if configured during installation) for triangulation. Note
that Shewchuk is required for operations involving Voronoi con-
structions.
GMT_VERBOSE
(-V) Determines the level of verbosity used by GMT programs.
Choose among 6 levels; each level adds to the verbosity of the
lower levels: quiet, nnormal (errors and warnings), compatibil-
ity warnings, verbose progress reports, long verbose progress
reports, debugging messages [c].
IO_COL_SEPARATOR
This setting determines what character will separate ASCII out-
put data columns written by GMT. Choose from tab, space, comma,
and none [tab].
IO_GRIDFILE_FORMAT
Default file format for grids, with optional scale, offset and
invalid value, written as ff[+sscale][+ooffset][+ninvalid]. The
2-letter format indicator can be one of [abcegnrs][bsifd]. See
grdconvert and Section grid-file-format of the GMT Technical
Reference and Cookbook for more information. You may the scale
as a for auto-adjusting the scale and/or offset of packed inte-
ger grids (=ID+sa is a shorthand for =ID+sa+oa). When invalid
is omitted the appropriate value for the given format is used
(NaN or largest negative). [nf].
IO_GRIDFILE_SHORTHAND
If true, all grid file names are examined to see if they use the
file extension shorthand discussed in Section grid-file-format
of the GMT Technical Reference and Cookbook. If false, no file-
name expansion is done [false].
IO_HEADER
(-h) Specifies whether input/output ASCII files have header
record(s) or not [false].
IO_LONLAT_TOGGLE
(-:) Set if the first two columns of input and output files con-
tain (latitude,longitude) or (y,x) rather than the expected
(longitude,latitude) or (x,y). false means we have (x,y) both on
input and output. true means both input and output should be
(y,x). IN means only input has (y,x), while OUT means only out-
put should be (y,x). [false].
IO_N_HEADER_RECS
Specifies how many header records to expect if -h is used [0].
Note: This will skip the specified number of records regardless
of what they are. Since any records starting with # is automat-
ically considered a header you will only specify a non-zero num-
ber in order to skip headers that do not conform to that conven-
tion.
IO_NAN_RECORDS
Determines what happens when input records containing NaNs for x
or y (and in some cases z) are read. Choose between skip, which
will simply report how many bad records were skipped, and pass
[Default], which will pass these records on to the calling pro-
grams. For most programs this will result in output records with
NaNs as well, but some will interpret these NaN records to indi-
cate gaps in a series; programs may then use that information to
detect segmentation (if applicable).
IO_NC4_CHUNK_SIZE
Sets the default chunk size for the lat and lon dimension of the
z variable. Very large chunk sizes and sizes smaller than 128
should be avoided because they can lead to unexpectedly bad per-
formance. Note that a chunk of a single precision floating point
variable of size 2896x2896 completely fills the chunk cache of
32MiB. Specify the chunk size for each dimension separated by a
comma, or auto for optimally chosen chunk sizes in the range
[128,256). Setting IO_NC4_CHUNK_SIZE will produce netCDF version
4 files, which can only be read with the netCDF 4 library,
unless all dimensions are less than 128 or classic is specified
for classic netCDF. [auto]
IO_NC4_DEFLATION_LEVEL
Sets the compression level for netCDF4 files upon output. Values
allowed are integers from 0 (no compression) to 9 (maximum com-
pression). Enabling a low compression level can dramatically
improve performance and reduce the size of certain data. While
higher compression levels further reduce the data size, they do
so at the cost of extra processing time. This parameter does not
apply to classic netCDF files. [3]
IO_SEGMENT_BINARY
Determines how binary data records with all values set to NaN
are interpreted. Such records are considered to be encoded seg-
ment headers in binary files provided the number of columns
equals or exceeds the current setting of IO_SEGMENT_BINARY [2].
Specify 0 or aoffa to deactivate the segment header determina-
tion.
IO_SEGMENT_MARKER
This holds the character we expect to indicate a segment header
in an incoming ASCII data or text table [>]. If this marker
should be different for output then append another character for
the output segment marker. The two characters must be separated
by a comma. Two marker characters have special meaning: B means
ablank linea and will treat blank lines as initiating a new seg-
ment, whereas N means aNaN recorda and will treat records with
all NaNs as initiating a new segment. If you choose B or N for
the output marker then the normal GMT segment header is replaced
by a blank or NaN record, respectively, and no segment header
information is written. To use B or N as regular segment markers
you must escape them with a leading backslash.
MAP_ANNOT_MIN_ANGLE
If the angle between the map boundary and the annotation base-
line is less than this minimum value (in degrees), the annota-
tion is not plotted (this may occur for certain oblique projec-
tions.) Give a value in the range [0,90]. [20]
MAP_ANNOT_MIN_SPACING
If an annotation would be plotted less than this minimum dis-
tance from its closest neighbor, the annotation is not plotted
(this may occur for certain oblique projections.) [0p]
MAP_ANNOT_OBLIQUE
This integer is a sum of 6 bit flags (most of which only are
relevant for oblique projections): If bit 1 is set (1), annota-
tions will occur wherever a gridline crosses the map boundaries,
else longitudes will be annotated on the lower and upper bound-
aries only, and latitudes will be annotated on the left and
right boundaries only. If bit 2 is set (2), then longitude anno-
tations will be plotted horizontally. If bit 3 is set (4), then
latitude annotations will be plotted horizontally. If bit 4 is
set (8), then oblique tick-marks are extended to give a projec-
tion equal to the specified tick length. If bit 5 is set (16),
tick-marks will be drawn normal to the border regardless of
gridline angle. If bit 6 is set (32), then latitude annotations
will be plotted parallel to the border. To set a combination of
these, add up the values in parentheses. [1].
MAP_ANNOT_OFFSET
Sets both MAP_ANNOT_OFFSET_PRIMARY and MAP_ANNOT_OFFSET_SEC-
ONDARY to the value specified. This setting is not included in
the gmt.conf file.
MAP_ANNOT_OFFSET_PRIMARY
Distance from end of tick-mark to start of annotation [5p].
MAP_ANNOT_OFFSET_SECONDARY
Distance from base of primary annotation to the top of the sec-
ondary annotation [5p] (Only applies to time axes with both pri-
mary and secondary annotations).
MAP_ANNOT_ORTHO
Determines which axes will get their annotations (for linear
projections) plotted orthogonally to the axes. Combine any w, e,
s, n, z (uppercase allowed as well). [we] (if nothing speci-
fied).
MAP_DEFAULT_PEN
Sets the default of all pens related to -W options. Prepend + to
overrule the color of the parameters MAP_GRID_PEN_PRIMARY,
MAP_GRID_PEN_SECONDARY, MAP_FRAME_PEN, MAP_TICK_PEN_PRIMARY, and
MAP_TICK_PEN_SECONDARY by the color of MAP_DEFAULT_PEN
[default,black].
MAP_DEGREE_SYMBOL
Determines what symbol is used to plot the degree symbol on geo-
graphic map annotations. Choose between ring, degree, colon, or
none [ring].
MAP_FRAME_AXES
Sets which axes to draw and annotate. Combine any uppercase W,
E, S, N, Z to draw and annotate west, east, south, north and/or
vertical (perspective view only) axis. Use lower case to draw
the axis only, but not annotate. Add an optional + to draw a
cube of axes in perspective view. [WESN].
MAP_FRAME_PEN
Pen attributes used to draw plain map frame [thicker,black].
MAP_FRAME_TYPE
Choose between inside, plain and fancy (thick boundary, alter-
nating black/white frame; append + for rounded corners) [fancy].
For some map projections (e.g., Oblique Mercator), plain is the
only option even if fancy is set as default. In general, fancy
only applies to situations where the projected x and y direc-
tions parallel the longitude and latitude directions (e.g.,
rectangular projections, polar projections). For situations
where all boundary ticks and annotations must be inside the maps
(e.g., for preparing geotiffs), chose inside. Finally, for
Cartesian plots you can also choose graph, which adds a vector
to the end of each axis. This works best when you reduce the
number of axes plotted.
MAP_FRAME_WIDTH
Width (> 0) of map borders for fancy map frame [5p].
MAP_GRID_CROSS_SIZE
Sets both MAP_GRID_CROSS_SIZE_PRIMARY and
MAP_GRID_CROSS_SIZE_SECONDARY to the value specified. This set-
ting is not included in the gmt.conf file.
MAP_GRID_CROSS_SIZE_PRIMARY
Size (>= 0) of grid cross at lon-lat intersections. 0 means draw
continuous gridlines instead [0p].
MAP_GRID_CROSS_SIZE_SECONDARY
Size (>= 0) of grid cross at secondary lon-lat intersections. 0
means draw continuous gridlines instead [0p].
MAP_GRID_CROSS_PEN
Sets both MAP_GRID_CROSS_PEN_PRIMARY and MAP_GRID_CROSS_PEN_SEC-
ONDARY to the value specified. This setting is not included in
the gmt.conf file.
MAP_GRID_PEN_PRIMARY
Pen attributes used to draw primary grid lines in dpi units or
points (append p) [default,black].
MAP_GRID_PEN_SECONDARY
Pen attributes used to draw secondary grid lines in dpi units or
points (append p) [thinner,black].
MAP_LABEL_OFFSET
Distance from base of axis annotations to the top of the axis
label [8p].
MAP_LINE_STEP
Determines the maximum length (> 0) of individual straight
line-segments when drawing arcuate lines [0.75p]
MAP_LOGO
(-U) Specifies if a GMT logo with system timestamp should be
plotted at the lower left corner of the plot [false].
MAP_LOGO_POS
(-U) Sets the justification and the position of the logo/time-
stamp box relative to the current plots lower left corner of the
plot [BL/-54p/-54p].
MAP_ORIGIN_X
(-X) Sets the x-coordinate of the origin on the paper for a new
plot [1i]. For an overlay, the default offset is 0.
MAP_ORIGIN_Y
(-Y) Sets the y-coordinate of the origin on the paper for a new
plot [1i]. For an overlay, the default offset is 0.
MAP_POLAR_CAP
Controls the appearance of gridlines near the poles for all
azimuthal projections and a few others in which the geographic
poles are plotted as points (Lambert Conic, Oblique Mercator,
Hammer, Mollweide, Sinusoidal and van der Grinten). Specify
either none (in which case there is no special handling) or
pc_lat/pc_dlon. In that case, normal gridlines are only drawn
between the latitudes -pc_lat/+*pc_lat*, and above those lati-
tudes the gridlines are spaced at the (presumably coarser)
pc_dlon interval; the two domains are separated by a small cir-
cle drawn at the pc_lat latitude [85/90]. Note for r-theta
(polar) projection where r = 0 is at the center of the plot the
meaning of the cap is reversed, i.e., the default 85/90 will
draw a r = 5 radius circle at the center of the map with less
frequent radial lines there.
MAP_SCALE_HEIGHT
Sets the height (> 0) on the map of the map scale bars drawn by
various programs [5p].
MAP_TICK_LENGTH
Sets both MAP_TICK_LENGTH_PRIMARY and MAP_TICK_LENGTH_SECONDARY
to the value specified. This setting is not included in the
gmt.conf file.
MAP_TICK_LENGTH_PRIMARY
The length of a primary major/minor tick-marks [5p/2.5p]. If
only the first value is set, the second is assumed to be 50% of
the first.
MAP_TICK_LENGTH_SECONDARY
The length of a secondary major/minor tick-marks [15p/3.75p]. If
only the first value is set, the second is assumed to be 25% of
the first.
MAP_TICK_PEN
Sets both MAP_TICK_PEN_PRIMARY and MAP_TICK_PEN_SECONDARY to the
value specified. This setting is not included in the gmt.conf
file.
MAP_TICK_PEN_PRIMARY
Pen attributes to be used for primary tick-marks in dpi units or
points (append p) [thinner,black].
MAP_TICK_PEN_SECONDARY
Pen attributes to be used for secondary tick-marks in dpi units
or points (append p) [thinner,black].
MAP_TITLE_OFFSET
Distance from top of axis annotations (or axis label, if
present) to base of plot title [14p].
MAP_VECTOR_SHAPE
Determines the shape of the head of a vector. Normally (i.e.,
for vector_shape = 0), the head will be triangular, but can be
changed to an arrow (1) or an open V (2). Intermediate settings
give something in between. Negative values (up to -2) are
allowed as well [0].
PROJ_AUX_LATITUDE
Only applies when geodesics are approximated by great circle
distances on an equivalent sphere. Select from authalic, geocen-
tric, conformal, meridional, parametric, or none [authalic].
When not none we convert any latitude used in the great circle
calculation to the chosen auxiliary latitude before doing the
distance calculation. See also PROJ_MEAN_RADIUS.
PROJ_ELLIPSOID
The (case sensitive) name of the ellipsoid used for the map pro-
jections [WGS-84]. Choose among:
Airy: Applies to Great Britain (1830)
Airy-Ireland: Applies to Ireland in 1965 (1830)
Andrae: Applies to Denmark and Iceland (1876)
APL4.9: Appl. Physics (1965)
ATS77: Average Terrestrial System, Canada Maritime provinces (1977)
Australian: Applies to Australia (1965)
Bessel: Applies to Central Europe, Chile, Indonesia (1841)
Bessel-Namibia: Same as Bessel-Schwazeck (1841)
Bessel-NGO1948: Modified Bessel for NGO 1948 (1841)
Bessel-Schwazeck: Applies to Namibia (1841)
Clarke-1858: Clarkeas early ellipsoid (1858)
Clarke-1866: Applies to North America, the Philippines (1866)
Clarke-1866-Michigan: Modified Clarke-1866 for Michigan (1866)
Clarke-1880: Applies to most of Africa, France (1880)
Clarke-1880-Arc1950: Modified Clarke-1880 for Arc 1950 (1880)
Clarke-1880-IGN: Modified Clarke-1880 for IGN (1880)
Clarke-1880-Jamaica: Modified Clarke-1880 for Jamaica (1880)
Clarke-1880-Merchich: Modified Clarke-1880 for Merchich (1880)
Clarke-1880-Palestine: Modified Clarke-1880 for Palestine (1880)
CPM: Comm. des Poids et Mesures, France (1799)
Delambre: Applies to Belgium (1810)
Engelis: Goddard Earth Models (1985)
Everest-1830: India, Burma, Pakistan, Afghanistan, Thailand (1830)
Everest-1830-Kalianpur: Modified Everest for Kalianpur (1956) (1830)
Everest-1830-Kertau: Modified Everest for Kertau, Malaysia & Singapore (1830)
Everest-1830-Pakistan: Modified Everest for Pakistan (1830)
Everest-1830-Timbalai: Modified Everest for Timbalai, Sabah Sarawak (1830)
Fischer-1960: Used by NASA for Mercury program (1960)
Fischer-1960-SouthAsia: Same as Modified-Fischer-1960 (1960)
Fischer-1968: Used by NASA for Mercury program (1968)
FlatEarth: As Sphere, but implies fast aFlat Eartha distance calculations (1984)
GRS-67: International Geodetic Reference System (1967)
GRS-80: International Geodetic Reference System (1980)
Hayford-1909: Same as the International 1924 (1909)
Helmert-1906: Applies to Egypt (1906)
Hough: Applies to the Marshall Islands (1960)
Hughes-1980: Hughes Aircraft Company for DMSP SSM/I grid products (1980)
IAG-75: International Association of Geodesy (1975)
Indonesian: Applies to Indonesia (1974)
International-1924: Worldwide use (1924)
International-1967: Worldwide use (1967)
Kaula: From satellite tracking (1961)
Krassovsky: Used in the (now former) Soviet Union (1940)
Lerch: For geoid modeling (1979)
Maupertius: Really old ellipsoid used in France (1738)
Mercury-1960: Same as Fischer-1960 (1960)
MERIT-83: United States Naval Observatory (1983)
Modified-Airy: Same as Airy-Ireland (1830)
Modified-Fischer-1960: Applies to Singapore (1960)
Modified-Mercury-1968: Same as Fischer-1968 (1968)
NWL-10D: Naval Weapons Lab (Same as WGS-72) (1972)
NWL-9D: Naval Weapons Lab (Same as WGS-66) (1966)
OSU86F: Ohio State University (1986)
OSU91A: Ohio State University (1991)
Plessis: Old ellipsoid used in France (1817)
SGS-85: Soviet Geodetic System (1985)
South-American: Applies to South America (1969)
Sphere: The mean radius in WGS-84 (for spherical/plate tectonics applications) (1984)
Struve: Friedrich Georg Wilhelm Struve (1860)
TOPEX: Used commonly for altimetry (1990)
Walbeck: First least squares solution by Finnish astronomer (1819)
War-Office: Developed by G. T. McCaw (1926)
WGS-60: World Geodetic System (1960)
WGS-66: World Geodetic System (1966)
WGS-72: World Geodetic System (1972)
WGS-84: World Geodetic System [Default] (1984)
Moon: Moon (IAU2000) (2000)
Mercury: Mercury (IAU2000) (2000)
Venus: Venus (IAU2000) (2000)
Mars: Mars (IAU2000) (2000)
Jupiter: Jupiter (IAU2000) (2000)
Saturn: Saturn (IAU2000) (2000)
Uranus: Uranus (IAU2000) (2000)
Neptune: Neptune (IAU2000) (2000)
Pluto: Pluto (IAU2000) (2000)
Note that for some global projections, GMT may use a spherical
approximation of the ellipsoid chosen, setting the flattening to
zero, and using a mean radius. A warning will be given when this
happens. If a different ellipsoid name than those mentioned here is
given, GMT will attempt to parse the name to extract the semi-major
axis (a in m) and the flattening. Formats allowed are:
a implies a zero flattening
a,inv_f where inv_f is the inverse flattening
a,b=b where b is the semi-minor axis (in m)
a,f=f where f is the flattening
This way a custom ellipsoid (e.g., those used for other planets) may
be used. Further note that coordinate transformations in mapproject
can also specify specific datums; see the mapproject man page for
further details and how to view ellipsoid and datum parameters.
PROJ_GEODESIC
Selects the algorithm to use for geodesic calculations. Choose
between Vincenty [Default], Rudoe, or Andoyer. The Andoyer algo-
rithm is only approximate (to within a few tens of meters) but
is up to 5 times faster. The Rudoe is given for legacy pur-
poses. The default Vincenty is accurate to about 0.5 mm.
PROJ_LENGTH_UNIT
Sets the unit length. Choose between cm, inch, or point [c (or
i)]. Note that, in GMT, one point is defined as 1/72 inch (the
PostScript definition), while it is often defined as 1/72.27
inch in the typesetting industry. There is no universal defini-
tion.
PROJ_MEAN_RADIUS
Applies when geodesics are approximated by great circle dis-
tances on an equivalent sphere or when surface areas are com-
puted. Select from mean (R_1), authalic (R_2), volumetric (R_3),
meridional, or quadratic [authalic].
PROJ_SCALE_FACTOR
Changes the default map scale factor used for the Polar Stereo-
graphic [0.9996], UTM [0.9996], and Transverse Mercator [1] pro-
jections in order to minimize areal distortion. Provide a new
scale-factor or leave as default.
PS_CHAR_ENCODING
(static) Names the eight bit character set being used for text
in files and in command line parameters. This allows GMT to
ensure that the PostScript output generates the correct charac-
ters on the plot.. Choose from Standard, Standard+, ISOLatin1,
ISOLatin1+, and ISO-8859-x (where x is in the ranges [1,10] or
[13,15]). See Appendix F for details [ISOLatin1+ (or Stan-
dard+)].
PS_COLOR_MODEL
Determines whether PostScript output should use RGB, HSV, CMYK,
or GRAY when specifying color [rgb]. Note if HSV is selected it
does not apply to images which in that case uses RGB. When
selecting GRAY, all colors will be converted to gray scale using
YIQ (television) conversion.
PS_COMMENTS
(static) If true we will issue comments in the PostScript file
that explain the logic of operations. These are useful if you
need to edit the file and make changes; otherwise you can set it
to false which yields a somewhat slimmer PostScript file
[false].
PS_IMAGE_COMPRESS
Determines if PostScript images are compressed using the
Run-Length Encoding scheme (rle), Lempel-Ziv-Welch compression
(lzw), DEFLATE compression (deflate[,level]), or not at all
(none) [deflate,5]. When specifying deflate, the compression
level (1a9) may optionally be appended.
PS_LINE_CAP
Determines how the ends of a line segment will be drawn. Choose
among a butt cap (default) where there is no projection beyond
the end of the path, a round cap where a semicircular arc with
diameter equal to the line-width is drawn around the end points,
and square cap where a half square of size equal to the
line-width extends beyond the end of the path [butt].
PS_LINE_JOIN
Determines what happens at kinks in line segments. Choose among
a miter join where the outer edges of the strokes for the two
segments are extended until they meet at an angle (as in a pic-
ture frame; if the angle is too acute, a bevel join is used
instead, with threshold set by PS_MITER_LIMIT), round join where
a circular arc is used to fill in the cracks at the kinks, and
bevel join which is a miter join that is cut off so kinks are
triangular in shape [miter].
PS_MEDIA
Sets the physical format of the current plot paper [a4 (or let-
ter)]. The following formats (and their widths and heights in
points) are recognized (Additional site-specific formats may be
specified in the gmt_custom_media.conf file in
$GMT_SHAREDIR/conf or ~/.gmt; see that file for details):
Media width height
o A0 2380 3368
o A1 1684 2380
o A2 1190 1684
o A3 842 1190
o A4 595 842
o A5 421 595
o A6 297 421
o A7 210 297
o A8 148 210
o A9 105 148
o A10 74 105
o B0 2836 4008
o B1 2004 2836
o B2 1418 2004
o B3 1002 1418
o B4 709 1002
o B5 501 709
o archA 648 864
o archB 864 1296
o archC 1296 1728
o archD 1728 2592
o archE 2592 3456
o flsa 612 936
o halfletter 396 612
o statement 396 612
o note 540 720
o letter 612 792
o legal 612 1008
o 11x17 792 1224
o tabloid 792 1224
o ledger 1224 792
For a completely custom format (e.g., for large format plotters)
you may also specify WxH, where W and H are in points unless you
append a unit to each dimension (c, i, m or p [Default]).
PS_MITER_LIMIT
Sets the threshold angle in degrees (integer in range [0,180])
used for mitered joins only. When the angle between joining line
segments is smaller than the threshold the corner will be bev-
elled instead of mitered. The default threshold is 35 degrees.
Setting the threshold angle to 0 implies the PostScript default
of about 11 degrees. Setting the threshold angle to 180 causes
all joins to be beveled.
PS_PAGE_COLOR
Sets the color of the imaging background, i.e., the paper
[white].
PS_PAGE_ORIENTATION
(* -P) Sets the orientation of the page. Choose portrait or
landscape [landscape].
PS_SCALE_X
Global x-scale (> 0) to apply to plot-coordinates before plot-
ting. Normally used to shrink the entire output down to fit a
specific height/width [1.0].
PS_SCALE_Y
Global y-scale (> 0) to apply to plot-coordinates before plot-
ting. Normally used to shrink the entire output down to fit a
specific height/width [1.0].
PS_TRANSPARENCY
Sets the transparency mode to use when preparing PS for render-
ing to PDF. Choose from Color, ColorBurn, ColorDodge, Darken,
Difference, Exclusion, HardLight, Hue, Lighten, Luminosity, Mul-
tiply, Normal, Overlay, Saturation, SoftLight, and Screen [Nor-
mal].
TIME_EPOCH
Specifies the value of the calendar and clock at the origin
(zero point) of relative time units (see TIME_UNIT). It is a
string of the form yyyy-mm-ddT[hh:mm:ss] (Gregorian) or
yyyy-Www-ddT[hh:mm:ss] (ISO) Default is 1970-01-01T00:00:00, the
origin of the UNIX time epoch.
TIME_INTERVAL_FRACTION
Determines if partial intervals at the start and end of an axis
should be annotated. If the range of the partial interval
exceeds the specified fraction of the normal interval stride we
will place the annotation centered on the partial interval
[0.5].
TIME_IS_INTERVAL
Used when input calendar data should be truncated and adjusted
to the middle of the relevant interval. In the following discus-
sion, the unit u can be one of these time units: (y year, o
month, u ISO week, d day, h hour, m minute, and s second).
TIME_IS_INTERVAL can have any of the following three values: (1)
OFF [Default]. No adjustment, time is decoded as given. (2) +nu.
Activate interval adjustment for input by truncate to previous
whole number of n units and then center time on the following
interval. (3) -nu. Same, but center time on the previous inter-
val. For example, with TIME_IS_INTERVAL = +1o, an input data
string like 1999-12 will be interpreted to mean
1999-12-15T12:00:00.0 (exactly middle of December), while if
TIME_IS_INTERVAL = off then that date is interpreted to mean
1999-12-01T00:00:00.0 (start of December) [off].
TIME_REPORT
Controls if a time-stamp should be issued at start of all
progress reports. Choose among TIMER_CLOCK (absolute time
stamp), TIMER_ELAPSED (time since start of session), or
TIMER_NONE [Default].
TIME_SYSTEM
Shorthand for a combination of TIME_EPOCH and TIME_UNIT, speci-
fying which time epoch the relative time refers to and what the
units are. Choose from one of the preset systems below (epoch
and units are indicated):
JD -4713-11-25T12:00:00 d (Julian Date)
MJD 1858-11-17T00:00:00 d (Modified Julian Date)
J2000 2000-01-01T12:00:00 d (Astronomical time)
S1985 1985-01-01T00:00:00 s (Altimetric time)
UNIX 1970-01-01T00:00:00 s (UNIX time)
RD0001 0001-01-01T00:00:00 s
RATA 0000-12-31T00:00:00 d
This parameter is not stored in the gmt.conf file but is trans-
lated to the respective values of TIME_EPOCH and TIME_UNIT.
TIME_UNIT
Specifies the units of relative time data since epoch (see
TIME_EPOCH). Choose y (year - assumes all years are 365.2425
days), o (month - assumes all months are of equal length y/12),
d (day), h (hour), m (minute), or s (second) [s].
TIME_WEEK_START
When weeks are indicated on time axes, this parameter determines
the first day of the week for Gregorian calendars. (The ISO
weekly calendar always begins weeks with Monday.) [Monday (or
Sunday)].
TIME_Y2K_OFFSET_YEAR
When 2-digit years are used to represent 4-digit years (see var-
ious FORMAT_DATEs), TIME_Y2K_OFFSET_YEAR gives the first year in
a 100-year sequence. For example, if TIME_Y2K_OFFSET_YEAR is
1729, then numbers 29 through 99 correspond to 1729 through
1799, while numbers 00 through 28 correspond to 1800 through
1828. [1950].
SEE ALSO
gmt(1), gmtdefaults(1), gmtcolors(5), gmtget(1), gmtset(1)
COPYRIGHT
2017, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
5.4.2 Jun 24, 2017 gmt.conf(5)
gmt5 5.4.2 - Generated Wed Jun 28 14:38:24 CDT 2017