# GMTDEFAULTS

NAME
SYNOPSIS
DESCRIPTION
GMT PARAMETERS
EXAMPLES
BUGS
SEE ALSO

## NAME

| gmtdefaults − To list current GMT defaults

## SYNOPSIS

| gmtdefaults −D[u|s] | −L

## DESCRIPTION

gmtdefaults lists the GMT parameter defaults if the option −D is used. There are three ways to change some of the settings: (1) Use the command gmtset, (2) use any texteditor to edit the file .gmtdefaults4 in your home or current directory (if you do not have this file, run gmtdefaults -D > ~/.gmtdefaults4 to get one with the system default settings), or (3) overrid any parameter by specifying one or more −−PARAMETER=VALUE statements on the commandline of any GMT command (PARAMETER and VALUE are any combination listed below). The first two options are permanent changes until explicitly changed back, while the last option is emphemeral and only applies to the single GMT command that received the override. 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.

| −D |  | 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].
| −L |  | Print the user’s currently active defaults to standard output.

| Your currently active defaults come from the .gmtdefaults4 file in the current working directory, if present; else from the .gmtdefaults4 file in your home directory, if present; else from the system defaults set at the time GMT was compiled.

## GMT PARAMETERS

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 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.

| ANNOT_MIN_ANGLE

| 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]

| ANNOT_MIN_SPACING

| 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]

| ANNOT_FONT_PRIMARY

| Font used for upper annotations, etc. [Helvetica]. Specify either the font number or the font name (case sensitive!). The 35 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

| ANNOT_FONT_SIZE_PRIMARY

| Font size (> 0) in points for map annotations. [14]

| ANNOT_FONT_SECONDARY

| Font to use for time axis secondary annotations. See ANNOT_FONT_PRIMARY for available fonts [Helvetica].

| ANNOT_FONT_SIZE_SECONDARY

| Font size (> 0) for time axis secondary annotations in points [16].

| ANNOT_OFFSET_PRIMARY

| Distance from end of tickmark to start of annotation [0.2c (or 0.075i)]. A negative offset will place the annotation inside the map border.

| ANNOT_OFFSET_SECONDARY

| Distance from base of primary annotation to the top of the secondary annotation [0.2c (or 0.075i)] (Only applies to time axes with both primary and secondary annotations).

| BASEMAP_AXES

| Sets which axes to draw and annotate. Case sensitive: Upper case means both draw and annotate, lower case means draw axis only. [WESN].

| BASEMAP_FRAME_RGB

| Color used to draw map boundaries and annotations. Give a red/green/blue triplet, with each element in the 0−255 range. Prepend ’+’ to replicate this color to the tick-, grid-, and frame-pens. [0/0/0] (black).

| BASEMAP_TYPE

| Choose between plain and fancy (thick boundary, alternating 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 directions parallel the lon and lat directions (e.g., rectangular projections, polar projections).

| CHAR_ENCODING

| 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 characters 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 Standard+)].

| COLOR_BACKGROUND

| 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_FOREGROUND

| 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)

| COLOR_IMAGE

| 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).

| COLOR_MODEL

Selects if color palette files contain RGB values (r,g,b in 0-255 range), HSV values (h in 0-360, s,v in 0-1 range), or CMYK values (c,m,y,k in 0-100% range). A COLOR_MODEL setting in the color palette file will override this setting. Internally, color interpolation takes place directly on the rgb values which can give unexpected hues, whereas interpolation directly on the hsv values better preserves the hues. Prepend the prefix "+" to force interpolation in the selected color system (does not apply to the CMYK system) [rgb].

| COLOR_NAN

| 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)

| D_FORMAT

| Output format (C language printf syntax) to be used when printing double precision floating point numbers. For geographic coordinates, see OUTPUT_DEGREE_FORMAT. [%lg].

| DEGREE_SYMBOL

| Determines what symbol is used to plot the degree symbol on geographic map annotations. Choose between ring, degree, colon, or none [ring].

| DOTS_PR_INCH

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].

| ELLIPSOID

| The (case sensitive) name of the ellipsoid used for the map projections [WGS-84]. Choose among

| WGS-84 |  | 1984 | World Geodetic System [Default] |  |  |  |
| OSU91A |  | 1991 | Ohio State University |  |  |  |
| OSU86F |  | 1986 | Ohio State University |  |  |  |
| Engelis |  | 1985 | Goodard Earth Models |  |  |  |
| SGS-85 |  | 1985 | Soviet Geodetic System |  |  |  |
| MERIT-83 |  | 1983 | United States Naval Observatory |  |  |  |
| GRS-80 |  | 1980 | International Geodetic Reference System |  |  |  |
| Lerch |  | 1979 | For geoid modelling |  |  |  |
| ATS77 |  | 1977 | Average Terrestrial System, Canada Maritime provinces |  |  |  |
| IAG-75 |  | 1975 | International Association of Geodesy |  |  |  |
| Indonesian |  |  | 1974 | Applies to Indonesia |  |  |
| WGS-72 |  | 1972 | World Geodetic System |  |  |  |
| NWL-10D |  | 1972 | Naval Weapons Lab (Same as WGS-72) |  |  |  |
| South-American |  |  | 1969 | Applies to South America |  |  |
| Fischer-1968 |  |  | 1968 | Used by NASA for Mercury program |  |  |
| Modified-Mercury-1968 |  |  |  |  | 1968 | Same as Fischer-1968 |
| GRS-67 |  | 1967 | International Geodetic Reference System |  |  |  |
| International-1967 |  |  |  | 1967 | Worldwide use |  |
| WGS-66 |  | 1966 | World Geodetic System |  |  |  |
| NWL-9D |  | 1966 | Naval Weapons Lab (Same as WGS-66) |  |  |  |
| Australian |  |  | 1965 | Applies to Australia |  |  |
| APL4.9 |  | 1965 | Appl. Physics |  |  |  |
| Kaula |  | 1961 | From satellite tracking |  |  |  |
| Hough |  | 1960 | Applies to the Marshall Islands |  |  |  |
| WGS-60 |  | 1960 | World Geodetic System |  |  |  |
| Fischer-1960 |  |  | 1960 | Used by NASA for Mercury program |  |  |
| Mercury-1960 |  |  | 1960 | Same as Fischer-1960 |  |  |
| Modified-Fischer-1960 |  |  |  |  | 1960 | Applies to Singapore |
| Fischer-1960-SouthAsia |  |  |  |  | 1960 | Same as Modified-Fischer-1960 |
| Krassovsky |  |  | 1940 | Used in the (now former) Soviet Union |  |  |
| War-Office |  |  | 1926 | Developed by G. T. McCaw |  |  |
| International-1924 |  |  |  | 1924 | Worldwide use |  |
| Hayford-1909 |  |  | 1909 | Same as the International 1924 |  |  |
| Helmert-1906 |  |  | 1906 | Applies to Egypt |  |  |
| Clarke-1880 |  |  | 1880 | Applies to most of Africa, France |  |  |
| Clarke-1880-Arc1950 |  |  |  | 1880 | Modified Clarke-1880 for Arc 1950 |  |
| Clarke-1880-IGN |  |  |  | 1880 | Modified Clarke-1880 for IGN |  |
| Clarke-1880-Jamaica |  |  |  | 1880 | Modified Clarke-1880 for Jamaica |  |
| Clarke-1880-Merchich |  |  |  |  | 1880 | Modified Clarke-1880 for Merchich |
| Clarke-1880-Palestine |  |  |  |  | 1880 | Modified Clarke-1880 for Palestine |
| Andrae |  | 1876 | Applies to Denmark and Iceland |  |  |  |
| Clarke-1866 |  |  | 1866 | Applies to North America, the Philippines |  |  |
| Clarke-1866-Michigan |  |  |  |  | 1866 | Modified Clarke-1866 for Michigan |
| Struve |  | 1860 | Friedrich Georg Wilhelm Struve |  |  |  |
| Clarke-1858 |  |  | 1858 | Clarke’s early ellipsoid |  |  |
| Airy | 1830 | Applies to Great Britain |  |  |  |  |
| Airy-Ireland |  |  | 1830 | Applies to Ireland in 1965 |  |  |
| Modified-Airy |  |  | 1830 | Same as Airy-Ireland |  |  |
| Bessel |  | 1841 | Applies to Central Europe, Chile, Indonesia |  |  |  |
| Bessel-Schwazeck |  |  |  | 1841 | Applies to Namibia |  |
| Bessel-Namibia |  |  | 1841 | Same as Bessel-Schwazeck |  |  |
| Bessel-NGO1948 |  |  | 1841 | Modified Bessel for NGO 1948 |  |  |
| Everest-1830 |  |  | 1830 | India, Burma, Pakistan, Afghanistan, Thailand |  |  |
| Everest-1830-Kalianpur |  |  |  |  | 1830 | Modified Everest for Kalianpur (1956) |
| Everest-1830-Kertau |  |  |  | 1830 | Modified Everest for Kertau, Malaysia & Singapore |  |
| Everest-1830-Timbalai |  |  |  |  | 1830 | Modified Everest for Timbalai, Sabah Sarawak |
| Everest-1830-Pakistan |  |  |  |  | 1830 | Modified Everest for Pakistan |
| Walbeck |  | 1819 | First least squares solution by Finnish astronomer |  |  |  |
| Plessis |  | 1817 | Old ellipsoid used in France |  |  |  |
| Delambre |  | 1810 | Applies to Belgium |  |  |  |
| CPM | 1799 | Comm. des Poids et Mesures, France |  |  |  |  |
| Maupertius |  |  | 1738 | Really old ellipsoid used in France |  |  |
| 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 a file with that name in the current directory, and read a single record that contains the ellipsoid name, year, major-axis (in m), minor-axis (in m), and flattening (f) 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. A negative flattening means GMT will recalculate flattening from the two radii.

| FIELD_DELIMITER

| This setting determines what character will separate ASCII output data columns written by GMT. Choose from tab, space, comma, and none [tab].

| FRAME_PEN

| Thickness of pen used to draw plain map frame in dpi units or points (append p) [1.25p].

| FRAME_WIDTH

| Width (> 0) of map borders for fancy map frame [0.2c (or 0.075i)].

| GLOBAL_X_SCALE

| 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].

| GLOBAL_Y_SCALE

| Same, but for y-coordinates [1.0].

| GRID_CROSS_SIZE_PRIMARY

| Size (>= 0) of grid cross at lon-lat intersections. 0 means draw continuous gridlines instead [0].

| GRID_PEN_PRIMARY

| Pen thickness used to draw grid lines in dpi units or points (append p) [0.25p].

| GRID_CROSS_SIZE_SECONDARY

| Size (>= 0) of grid cross at secondary lon-lat intersections. 0 means draw continuous gridlines instead [0].

| GRID_FORMAT

Default file format for grids, with optional scale, offset and invalid value, written as ff/scale/offset/invalid. The 2-letter format indicator can be one of [bcnsr][bsifd]. The first letter indicates native GMT binary, old format NetCDF, COARDS-compliant NetCDF, Surfer format or Sun Raster format. The second letter stands for byte, short, int, float and double, respectively. When /invalid is omitted the appropriate value for the given format is used (NaN or largest negative). When /scale/offset is omitted, /1.0/0.0 is used. [nf].

| GRID_PEN_SECONDARY

| Pen thickness used to draw grid lines in dpi units or points (append p) [0.5p].

| GRIDFILE_SHORTHAND

| 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].

| HEADER_FONT

| Font to use when plotting headers. See ANNOT_FONT_PRIMARY for available fonts [Helvetica].

| HEADER_FONT_SIZE

| Font size (> 0) for header in points [36].

| HEADER_OFFSET

| Distance from top of axis annotations (or axis label, if present) to base of plot header [0.5c (or 0.1875i)].

| HISTORY

| If TRUE, passes the history of past common command options via the hidden .gmtcommands4 file [TRUE].

| HSV_MIN_SATURATION

| Minimum saturation (0−1) assigned for most negative intensity value [1.0].

| HSV_MAX_SATURATION

| Maximum saturation (0−1) assigned for most positive intensity value [0.1].

| HSV_MIN_VALUE

| Minimum value (0−1) assigned for most negative intensity value [0.3].

| HSV_MAX_VALUE

| Maximum value (0−1) assigned for most positive intensity value [1.0].

| INPUT_CLOCK_FORMAT

| 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].

| INPUT_DATE_FORMAT

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 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 consistent, e.g., you cannot specify months if you don’t specify years. Examples are yyyyWwwd, yyyy-Www, etc. [yyyy-mm-dd].

| INTERPOLANT

| Determines if linear (linear), Akima’s spline (akima), or natural cubic spline (cubic) should be used for 1-D interpolations in various programs [akima].

| IO_HEADER

| (* −H) Specifies whether input/output ASCII files have header record(s) or not [FALSE].

| N_HEADER_RECS

| Specifies how many header records to expect if −H is turned on [1].

| LABEL_FONT

| Font to use when plotting labels below axes. See ANNOT_FONT_PRIMARY for available fonts [Helvetica].

| LABEL_FONT_SIZE

| Font size (> 0) for labels in points [24].

| LABEL_OFFSET

| Distance from base of axis annotations to the top of the axis label [0.3c (or 0.1125i)].

| LINE_STEP

| Determines the maximum length (> 0) of individual straight line-segments when drawing arcuate lines [0.025c (or 0.01i)]

| MAP_SCALE_FACTOR

| Changes the default map scale factor used for the Polar Stereographic [0.9996], UTM [0.9996], and Transverse Mercator [1] projections in order to minimize areal distortion. Provide a new scale-factor or leave as default.

| MAP_SCALE_HEIGHT

| Sets the height (> 0) on the map of the map scale bars drawn by various programs [0.2c (or 0.075i)].

| MEASURE_UNIT

| 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].

| OBLIQUE_ANNOTATION

This integer is a sum of 6 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 annotations 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 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. 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].

| OUTPUT_CLOCK_FORMAT

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].

| OUTPUT_DATE_FORMAT

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 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 examples, 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 consistant, e.g., you cannot specify months if you don’t specify years. As examples, try yyyyWww, yy-W-ww-d, etc. 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) [yyyy-mm-dd].

| OUTPUT_DEGREE_FORMAT

| 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]. The various terms have the following purpose:

| + | means output longitude in the 0 to 360 range [-180/+180] |
| - | means output longitude in the -360 to 0 range [-180/+180] |
| D | Use D_FORMAT for floating point degrees. |
| ddd | Fixed format integer degrees |
| : | delimiter used |
| mm | Fixed format integer arc minutes |
| ss | Fixed format integer arc seconds |
| F | Encode sign using WESN suffix |

| The default is +D.

| PAGE_COLOR

| 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).

| PAGE_ORIENTATION

| (* −P) Sets the orientation of the page. Choose portrait or landscape [landscape].

| PAPER_MEDIA

| 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 |  |

For a completely custom format (e.g., for large format plotters) you may also specify Custom_WxH, where W and H are in points. 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 Bounding Box is the paper dimension].

| PLOT_CLOCK_FORMAT

| Formatting template that indicates how an output clock string is to be plotted. This template is then used to guide the formatting of clock strings in plot annotations. See OUTPUT_CLOCK_FORMAT for details. [hh:mm:ss].

| PLOT_DATE_FORMAT

| 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 OUTPUT_DATE_FORMAT 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 "Week ##". Both of these text strings will be affected by the TIME_LANGUAGE setting. [yyyy-mm-dd].

| PLOT_DEGREE_FORMAT

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 OUTPUT_DEGREE_FORMAT 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.

| 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, 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 latitudes the gridlines are spaced at the (presumably coarser) pc_dlon interval; the two domains are separated by a small circle drawn at the pc_lat latitude [85/90].

| PS_COLOR

| Determines whether PostScript output should use RGB, HSV, or CMYK when specifying color [RGB]. Note if HSV is selected it does not apply to images which in that case uses RGB.

| PS_IMAGE_COMPRESS

| Determines if PostScript images are compressed using the Run-Length Encoding scheme (rle), LZW compression (lzw), or not at all (none) [none].

| PS_IMAGE_FORMAT

| Determines whether images created in PostScript should use ASCII or binary format. The latter takes up less space and executes faster but may choke some printers, especially those off serial ports. Select ascii or bin [ascii].

| 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 linewidth is drawn around the end points, and square cap where a half square of size equal to the linewidth 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 picture 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_MITER_LIMIT

| Sets the threshold angle (integer in 0-180 range) used for mitered joins. 0 and 180 are special flag values that imply the PostScript default [11] and always bevels, respectively. Other values sets the acute angle used to decide between mitered and bevelled.

| PS_VERBOSE

| 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].

| TICK_LENGTH

| 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)].

| TICK_PEN

| The pen thickness to be used for tickmarks in dpi units or points (append p) [0.5p].

| TIME_FORMAT_PRIMARY

| Controls how primary month-, week-, and weekday-names are formatted. 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.

| TIME_FORMAT_SECONDARY

| Controls how secondary month-, week-, and weekday-names are formatted. 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.

| TIME_EPOCH

| Specifying this parameter also sets TIME_SYSTEM to OTHER. It is a string of the form yyyy-mm-ddT[hh:mm:ss] (Gregorian) or yyyy-Www-ddT[hh:mm:ss] (ISO) indicating the value of the calendar and clock at the origin (zero point) of relative time units (see TIME_UNIT).

| TIME_IS_INTERVAL

Used when input calendar data should be truncated and adjusted to the middle of the relevant interval. In the following discussion, the unit u can be one of these time units: (y year, o month, u ISO week, d day, h hour, m minute, and c second). TIME_IS_INTERVAL can have any of the following three values: (1) OFF [Default]. No adjustment, time is decoded as given. (2) +n u. Activate interval adjustment for input by truncate to previous whole number of n units and then center time on the following interval. (3) -n u. Same, but center time on the previous interval. 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 1999-12-1T00:00:00.0 (start of December).

| 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_LANGUAGE

| Language to use when plotting calendar items such as months and days. Select from:

| BR | Brazilian Portuguese |
| CN1 | Simplified Chinese |
| CN2 | Traditional Chinese |
| DE | German |
| DK | Danish |
| EH | Basque |
| ES | Spanish |
| FI | Finnish |
| FR | French |
| GR | Greek |
| HU | Hungarian |
| IE | Irish |
| IL | Hebrew |
| IS | Icelandic |
| IT | Italian |
| JP | Japanese |
| NL | Dutch |
| NO | Norwegian |
| PL | Polish |
| PT | Portuguese |
| RU | Russian |
| SE | Swedish |
| SG | Scottish Gaelic |
| TO | Tongan |
| TR | Turkish |
| UK | British English |
| US | US English |

| If your language is not supported, please examine the $GMTHOME/share/time/us.d file and make a similar file. Please submit it to the GMT Developers for official inclusion.

| TIME_SYSTEM

| Determines 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 | Julian Date, -4713-11-25T12:00:00 d |  |
| MJD | Modified Julian Date, 1858-11-27T00:00:00 d |  |
| J2000 |  | 2000-01-01T00:00:00 d |
| S1985 |  | 1985-01-01T00:00:00 c |
| UNIX | 1970-01-01T00:00:00 c |  |
| RD0001 |  | 0001-01-01T00:00:00 c |
| RATA | 0000-12-31T00:00:00 d |  |

| or specify OTHER and supply your own TIME_EPOCH and TIME_UNIT settings [J2000].

| TIME_UNIT

| This parameter is active only when TIME_SYSTEM is set to OTHER, and specifies the units of relative time data. 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 c (second).

| 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)].

| UNIX_TIME

| (* −U) Specifies if a UNIX system time stamp should be plotted at the lower left corner of the plot [FALSE].

| UNIX_TIME_POS

| (* −U) Sets the position of the UNIX time stamp relative to the current plots lower left corner [-2c/-2c (or -0.75i/-0.75i)].

| 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].

| VERBOSE

| (* −V) Determines if GMT programs should display run-time information or run silently [FALSE].

| X_AXIS_LENGTH

| Sets the default length (> 0) of the x-axis [25c (or 9i)].

| Y_AXIS_LENGTH

| Sets the default length (> 0) of the y-axis [15c (or 6i)].

| X_ORIGIN

| (* −X) 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.

| Y_ORIGIN

| (* −Y) 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.

| Y2K_OFFSET_YEAR

| When 2-digit years are used to represent 4-digit years (see various DATE_FORMATs), Y2K_OFFSET_YEAR gives the first year in a 100-year sequence. For example, if 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].

| XY_TOGGLE

| (* −:) Set if the first two columns of input and output files contain (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 output should be (y,x). [FALSE].

| Y_AXIS_TYPE

| Determines if the annotations for a y-axis (for linear projections) should be plotted horizontally (hor_text) or vertically (ver_text) [hor_text].

## EXAMPLES

| To get a copy of the GMT parameter defaults in your home directory, run gmtdefaults −D > ~/.gmtdefaults4 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.

## BUGS

| If you have typographical errors in your .gmtdefaults4 file(s), a warning message will be issued, and the GMT defaults for the affected parameters will be used.

## SEE ALSO

| GMT(l), gmtset(l)