gmtdefaults(1) To list current GMT defaults


gmtdefaults -D[u|s] | -L


gmtdefaults lists the GMT parameter defaults if the option -D is used. To change some of the settings, use any texteditor to edit the file .gmtdefaults in your home or current directory. If you do not have this file in your home or current directory, run gmtdefaults -D > ~/.gmtdefaults to get the system settings. GMT can provide default values in US or SI units. This choice is determined by the contents of the gmt.conf file in GMT's share directory.'
Print the system GMT defaults to standard output. Append u for US defaults or s for SI defaults. [-D alone gives current choice in gmt.conf].
Print the user's currently active defaults to standard output.'


The following is a list of the 58 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 [ ]. Those marked * can be set on the command line as well (the corresponding option is given in parentheses). 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 MEASURE_UNIT). You can explicitly specify the unit used for distances and lengths by appending c (cm), i (inch), m (meter), or p {points). When no unit is indicated the value will be assumed to be in the unit set by MEASURE_UNIT. Note that the printer resolution DOTS_PR_INCH is always the number of dots or pixels per inch. Several parameters take only TRUE or FALSE.
If the angle between the map boundary and the annotation baseline is less than this minimum value (in degrees), the annotation is not plotted (this may occur for certain oblique projections.) Give a value in the range 0-90. [20]
If an annotation would be plotted less than this minimum distance from its closest neighbor, the annotation is not plotted (this may occur for certain oblique projections.) [0]
Font used for tick mark annotations etc [Helvetica]. Specify either the font number or the font name (case sensitive!). The 39 available fonts are:

        0 Helvetica

        1 Helvetica-Bold

        2 Helvetica-Oblique

        3 Helvetica-BoldOblique

        4 Times-Roman

        5 Times-Bold

        6 Times-Italic

        7 Times-BoldItalic

        8 Courier

        9 Courier-Bold

        10 Courier-Oblique

        11 Courier-BoldOblique

        12 Symbol

        13 AvantGarde-Book

        14 AvantGarde-BookOblique

        15 AvantGarde-Demi

        16 AvantGarde-DemiOblique

        17 Bookman-Demi

        18 Bookman-DemiItalic

        19 Bookman-Light

        20 Bookman-LightItalic

        21 Helvetica-Narrow

        22 Helvetica-Narrow-Bold

        23 Helvetica-Narrow-Oblique

        24 Helvetica-Narrow-BoldOblique

        25 NewCenturySchlbk-Roman

        26 NewCenturySchlbk-Italic

        27 NewCenturySchlbk-Bold

        28 NewCenturySchlbk-BoldItalic

        29 Palatino-Roman

        30 Palatino-Italic

        31 Palatino-Bold

        32 Palatino-BoldItalic

        33 ZapfChancery-MediumItalic

        34 ZapfDingbats

        35 Ryumin-Light-EUC-H

        36 Ryumin-Light-EUC-V

        37 GothicBBB-Medium-EUC-H

        38 GothicBBB-Medium-EUC-V
Font size (> 0) in points for map annotations. [14]
Distance from end of tickmark to start of annotation [0.2c (or 0.075i)]. A negative offset will place the anotation inside the map border.
Sets which axes to draw and annotate. Case sensitive: Upper case means both draw and annotate, lower case means draw axis only. [WESN].
Color used to draw map boundaries and annotations. Give a red/green/blue triplet, with each element in the 0-255 range. [0/0/0] (black).
Choose between plain and fancy (thick boundary, alternating black/white frame) [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 directions parallel the lon and lat directions (e.g., rectangular projections, polar projections).
Color used for the background of images (i.e., when z < lowest colortable entry). Give a red/green/blue triplet, with each element in the 0-255 range. [0/0/0] (black)
Color used for the foreground of images (i.e., when z > highest colortable entry). Give a red/green/blue triplet, with each element in the 0-255 range. [255/255/255] (white)
Selects which operator to use when rendering bit-mapped color images. Due to the lack of the colorimage operator in some PostScript implementations, GMT offers 2 different options:

        adobe (Adobe's colorimage definition)  [Default].'

        tiles (Plot image as many individual rectangles).

Selects if color palette files contain rgb values (r,g,b in 0-255 range) or HSV values (h = 0-360, s,v in 0-1 range) [rgb].
Color used for the non-defined areas of images (i.e., where z == NaN). Give a red/green/blue triplet, with each element in the 0-255 range. [128/128/128] (gray)
Output format (C language syntax) to be used when printing double precision floating point numbers If it is NOT a 'g'-type format (as the default is), the format is used directly in anotations. [%lg].
Output format to be used when annotating map boundaries. Choose between 12 formats:

        0 Longitudes go from 0 to 360, latitudes from -90 to 90 [Default].

        1 Longitudes go from -180 to 180, latitudes from -90 to 90.

        2 Longitudes are unsigned 0 to 180, latitudes unsigned 0 to 90.

        3 Same as 2, but with letters W, E, S, or N appended as appropriate.

        4 Same as 0, with decimal degrees instead of degrees, minutes, and seconds.

        5 Same as 1, with decimal degrees instead of degrees, minutes, and seconds.

        6 Same as 4, but with letters W, E, S, or N appended as appropriate.

        7 Same as 5, but with letters W, E, S, or N appended as appropriate.

        8 Same as 0, with degrees and decimal minutes instead of degrees, minutes, and seconds.

        9 Same as 1, with degrees and decimal minutes instead of degrees, minutes, and seconds.

        10 Same as 2, with degrees and decimal minutes instead of degrees, minutes, and seconds.

        11 Same as 3, with degrees and decimal minutes instead of degrees, minutes, and seconds.

Add 100 to these values to use the large degree symbol character (octal 217) [Default is the small degree symbol (octal 312)].

Resolution of the plotting device (dpi). Note that in order to be as compact as possible, GMT PostScript output uses integer formats only so the resolution should be set depending on what output device you are using. E.g, using 300 and sending the output to a Linotype 300 phototypesetter (2470 dpi) will not take advantage of the extra resolution (i.e., positioning on the page and line thicknesses are still only done in steps of 1/300 inch; of course, text will look smoother) [300].
The (case sensitive) name of the ellipsoid used for the map projections [WGS-84]. Choose among

WGS-84 1984 World Geodetic System
GRS-80 1980 International Geodetic Reference System
WGS-72 1972 World Geodetic System
WGS-66 1966 World Geodetic System
Australian 1965 Used down under
Krassovsky 1940 Used in the Soviet Union
International 1924 Worldwide use
Hayford-1909 1909 Same as the International 1924
Clarke-1880 1880 Most of Africa, France
Clarke-1866 1866 North America, the Phillipines
Airy 1830 Great Britain
Bessel 1841 Central Europe, Chile, Indonesia
Everest 1830 India, Burma, Pakistan, Afghanistan, Thailand, etc.
Sphere 1980 The mean radius in GRS-80 (for spherical/plate tectonics applications)

Note that for some global projections, GMT may default to GRS-80 Sphere regardless of ellipsoid actually chosen. A warning will be given when this happens. If a different ellipsoid name than those mentioned here is given, GMT will attempt to open this name as a file and read the ellipsoid name, year, major-axis (in m), minor-axis (in m), and flattening from the first record, where the fields must be separated by white-space (not commas). This way a custom ellipsoid (e.g., those used for other planets) may be used.

Thickness of pen used to draw plain map frame in dpi units or points (append p) [5].
Width (> 0) of map borders for fancy map frame [0.2c (or 0.075i)].
Global x-scale (> 0) to apply to plot-coordinates before plotting. Normally used to shrink the entire output down to fit a specific height/width [1.0].
Same, but for y-coordinates [1.0].
Size (>= 0) of grid cross at lon-lat intersections. 0 means draw continuous gridlines instead [0].
Pen thickness used to draw grid lines in dpi units or points (append p) [1].
If TRUE, all gridfile names are examined to see if they use the file extension shorthand discussed in Section 4.17 of the GMT Technical Reference and Cookbook. If FALSE, no filename expansion is done [FALSE].
Font to use when plotting headers. See ANOT_FONT for available fonts [Helvetica].
Font size (> 0) for header in points [36].
Minimum saturation (0-1) assigned for most negative intensity value [1.0].
Maximum saturation (0-1) assigned for most positive intensity value [0.1].
Minimum value (0-1) assigned for most negative intensity value [0.3].
Maximum value (0-1) assigned for most positive intensity value [1.0].
Determines if linear (linear), Akima's spline (akima), or natural cubic spline (cubic) should' be used for 1-D interpolations in various programs [akima].
Specifies whether input/output ASCII files have header record(s) or not [FALSE].
Specifies how many header records to expect if -H is turned on [1].
Font to use when plotting labels below axes. See ANOT_FONT for available fonts [Helvetica].
Font size (> 0) for labels in points [24].
Determines the maximum length (> 0) of individual straight line-segments when drawing arcuate lines [0.025c (or 0.01i)]
Sets the central scale factor (> 0) used for the Polar Stereographic and Transverse Mercator projections. Typically, it is set to 0.9996 to minimize areal distortion [0.9996].
Sets the height (> 0) on the map of the map scalebars drawn by various programs [0.2c (or 0.075i)].
Sets the unit length. Choose between cm, inch, m, and point. [cm]. 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 definition.
N_COPIES * (-c)
Number of plot copies to make [1].
This integer is a sum of 5 bit flags (most of which only are relevant for oblique projections): If bit 1 is set (1), annotations will occur wherever a gridline crosses the map boundaries, else longitudes will be annotated on the lower and upper boundaries only, and latitudes will be annotated on the left and right boundaries only. If bit 2 is set (2), then longitude anotations will be plotted horizontally. If bit 3 is set (4), then latitude anotations will be plotted horizontally. If bit 4 is set (8), then oblique tickmarks are extended to give a projection equal to the specified tick_length. If bit 5 is set (16), tickmarks will be drawn normal to the border regardless of gridline angle. To set a combination of these, add up the values in parentheses. [1].
Sets the color of the imaging background, i.e., the paper. Give a red/green/blue triplet, with each element in the 0-255 range. [255/255/255] (white)
Sets the orientation of the page. Choose portrait or landscape [landscape].
Sets the physical format of the current plot paper [A4]. The following formats (and their widths and heights in points) are recognized (Additional site-specific formats may be specified in the gmtmedia.d file in $GMTHOME/share; see that file for details):

        Media width height

        A0 2380 3368

        A1 1684 2380

        A2 1190 1684

        A3 842 1190

        A4 595 842

        A5 421 595

        A6 297 421

        A7 210 297

        A8 148 210

        A9 105 148

        A10 74 105

        B0 2836 4008

        B1 2004 2836

        B2 1418 2004

        B3 1002 1418

        B4 709 1002

        B5 501 709

        archA 648 864

        archB 864 1296

        archC 1296 1728

        archD 1728 2592

        archE 2592 3456

        flsa 612 936

        halfletter 396 612

        note 540 720

        letter 612 792

        legal 612 1008

        11x17 792 1224

        ledger 1224 792

To force the printer to request a manual paper feed, append '-' to the media name, e.g., A3- will require the user to insert a A3 paper into the printer's' manual feed slot. To indicate you are making an EPS file, append '+' to the media name. Then, GMT will attempt to issue a tight bounding box [Default is the paper dimension].

Determines whether images created in PostScript should use hexadecimal (i.e., ascii) or binary format. The latter takes up only half as much space and executes faster but may choke some printers, especially those off serial ports. Select hex or bin [hex].
The length of a tickmark. Normally, tickmarks are drawn on the outside of the map boundaries. To select interior tickmarks, use a negative tick_length [0.2c (or 0.075i)].
The pen thickness to be used for tickmarks in dpi units or points (append p) [2].
Specifies if a UNIX system time stamp should be plotted at the lower left corner of the plot [FALSE].
Sets the position of the UNIX time stamp relative to the current plots lower left corner [-2c/-2c (or -0.75i/-0.75i)].
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). Intermediate settings gives something in between [0].
Determines if GMT programs should display run-time information or run silently [FALSE].
Determines if GMT PostScript output should include font re-encoding for accented European characters. See Cookbook section 4.16 and Appendix H for details [TRUE].
Sets the default length (> 0) of the x-axis [25c (or 9i)].
Sets the default length (> 0) of the y-axis [15c (or 6i)].
Sets the x-coordinate of the origin on the paper for a new plot [2.5c (or 1i)]. For an overlay, the default offset is 0.
Sets the y-coordinate of the origin on the paper for a new plot [2.5c (or 1i)]. For an overlay, the default offset is 0.
XY_TOGGLE * (-:)
Set if the first two columns of input files contain (latitude,longitude) or (y,x) rather than the expected (longitude,latitude) or (x,y) [FALSE].
Determines if the annotations for a y-axis (for linear projections) should be plotted horizontally (hor_text) or vertically (ver_text) [hor_text].


To get a copy of the GMT parameter defaults in your home directory, run

gmtdefaults -D > ~/.gmtdefaults

You may now change the settings by editing this file using a text editor of your choice, or use gmtset to change specified parameters on the command line.


If you have typographical errors in your .gmtdefaults file(s), a warning message will be issued, and the GMT defaults for the affected parameters will be used.