Provided by: gmt_4.5.11-1build1_amd64
psxy - Plot lines, polygons, and symbols on maps
psxy files -Jparameters -Rwest/east/south/north[r] [ -A[m|p] ] [ -B[p|s]parameters ] [ -Ccptfile ] [ -Ddx/dy ] [ -E[x|y|X|Y][n][cap][/[-|+]pen] ] [ -Gfill ] [ -H[i][nrec] ] [ -Iintens ] [ -K ] [ -L ] [ -N ] [ -O ] [ -P ] [ -S[symbol][size] ] [ -U[just/dx/dy/][c|label] ] [ -V ] [ -W[-|+][pen] ] [ -X[a|c|r][x-shift[u]] ] [ -Y[a|c|r][y-shift[u]] ] [ -:[i|o] ] [ -bi[s|S|d|D[ncol]|c[var1/...]] ] [ -ccopies ] [ -fcolinfo ] [ -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] ] [ -m[flag] ]
psxy reads (x,y) pairs from files [or standard input] and generates PostScript code that will plot lines, polygons, or symbols at those locations on a map. If a symbol is selected and no symbol size given, then psxy will interpret the third column of the input data as symbol size. Symbols whose size is <= 0 are skipped. If no symbols are specified then the symbol code (see -S below) must be present as last column in the input. Multiple segment files may be plotted using the -m option. If -S is not used, a line connecting the data points will be drawn instead. To explicitly close polygons, use -L. Select a fill with -G. If -G is set, -W will control whether the polygon outline is drawn or not. If a symbol is selected, -G and -W determines the fill and outline/no outline, respectively. The PostScript code is written to standard output. files List one or more file-names. If no files are given, psxy will read standard input. Use -T to ignore all input files, including standard input (see below). -J Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or width in UNIT (upper case modifier). UNIT is cm, inch, or m, depending on the MEASURE_UNIT setting in .gmtdefaults4, but this can be overridden on the command line by appending c, i, or m to the scale/width value. When central meridian is optional, default is center of longitude range on -R option. Default standard parallel is the equator. For map height, max dimension, or min dimension, append h, +, or - to the width, respectively. More details can be found in the psbasemap man pages. CYLINDRICAL PROJECTIONS: -Jclon0/lat0/scale (Cassini) -Jcyl_stere/[lon0/[lat0/]]scale (Cylindrical Stereographic) -Jj[lon0/]scale (Miller) -Jm[lon0/[lat0/]]scale (Mercator) -Jmlon0/lat0/scale (Mercator - Give meridian and standard parallel) -Jo[a]lon0/lat0/azimuth/scale (Oblique Mercator - point and azimuth) -Jo[b]lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points) -Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and pole) -Jq[lon0/[lat0/]]scale (Cylindrical Equidistant) -Jtlon0/[lat0/]scale (TM - Transverse Mercator) -Juzone/scale (UTM - Universal Transverse Mercator) -Jy[lon0/[lat0/]]scale (Cylindrical Equal-Area) CONIC PROJECTIONS: -Jblon0/lat0/lat1/lat2/scale (Albers) -Jdlon0/lat0/lat1/lat2/scale (Conic Equidistant) -Jllon0/lat0/lat1/lat2/scale (Lambert Conic Conformal) -Jpoly/[lon0/[lat0/]]scale ((American) Polyconic) AZIMUTHAL PROJECTIONS: -Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area) -Jelon0/lat0[/horizon]/scale (Azimuthal Equidistant) -Jflon0/lat0[/horizon]/scale (Gnomonic) -Jglon0/lat0[/horizon]/scale (Orthographic) -Jglon0/lat0/altitude/azimuth/tilt/twist/Width/Height/scale (General Perspective). -Jslon0/lat0[/horizon]/scale (General Stereographic) MISCELLANEOUS PROJECTIONS: -Jh[lon0/]scale (Hammer) -Ji[lon0/]scale (Sinusoidal) -Jkf[lon0/]scale (Eckert IV) -Jk[s][lon0/]scale (Eckert VI) -Jn[lon0/]scale (Robinson) -Jr[lon0/]scale (Winkel Tripel) -Jv[lon0/]scale (Van der Grinten) -Jw[lon0/]scale (Mollweide) NON-GEOGRAPHICAL PROJECTIONS: -Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r)) -Jxx-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log, and power scaling) -R xmin, xmax, ymin, and ymax specify the Region of interest. For geographic regions, these limits correspond to west, east, south, and north and you may specify them in decimal degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and upper right map coordinates are given instead of w/e/s/n. The two shorthands -Rg and -Rd stand for global domain (0/360 and -180/+180 in longitude respectively, with -90/+90 in latitude). Alternatively, specify the name of an existing grid file and the -R settings (and grid spacing, if applicable) are copied from the grid. For calendar time coordinates you may either give (a) relative time (relative to the selected TIME_EPOCH and in the selected TIME_UNIT; append t to -JX|x), or (b) absolute time of the form [date]T[clock] (append T to -JX|x). At least one of date and clock must be present; the T is always required. The date string must be of the form [-]yyyy[-mm[-dd]] (Gregorian calendar) or yyyy[-Www[-d]] (ISO week calendar), while the clock string must be of the form hh:mm:ss[.xxx]. The use of delimiters and their type and positions must be exactly as indicated (however, input, output and plot formats are customizable; see gmtdefaults).
No space between the option flag and the associated arguments. -A By default line segments are drawn as great circle arcs. To draw them as straight lines, use the -A flag. Alternatively, add m to draw the line by first following a meridian, then a parallel. Or append p to start following a parallel, then a meridian. (This can be practical to draw a lines along parallels, for example). -B Sets map boundary annotation and tickmark intervals; see the psbasemap man page for all the details. -C Give a color palette file. If -S is set, let symbol fill color be determined by the z-value in the third column. Additional fields are shifted over by one column (optional size would be 4th rather than 3rd field, etc.). If -S is not set, then psxy expects the user to supply a multisegment line or polygon file (requires -m) where each segment header contains a -Zval string. The val will control the color of the line or polygon (if -L is set) via the cpt file. -D Offset the plot symbol or line locations by the given amounts dx/dy [Default is no offset]. If dy is not given it is set equal to dx. -E Draw error bars. Append x and/or y to indicate which bars you want to draw (Default is both x and y). The x and/or y errors must be stored in the columns after the (x,y) pair [or (x,y,size) triplet]. The cap parameter indicates the length of the end-cap on the error bars [0.25c (or 0.1i)]. Pen attributes for error bars may also be set (see SPECIFYING PENS below) [Defaults: width = 0.25p, color = black, texture = solid]. A leading + will use the lookup color (via -C) for both symbol fill and error pen color, while a leading - will set error pen color and turn off symbol fill. If upper case X and/or Y is used we will instead draw "box-and-whisker" (or "stem-and-leaf") symbols. The x (or y) coordinate is then taken as the median value, and 4 more columns are expected to contain the minimum (0% quantile), the 25% quantile, the 75% quantile, and the maximum (100% quantile) values. The 25-75% box may be filled by using -G. If n is appended to X (or Y) we draw a notched "box-and-whisker" symbol where the notch width reflects the uncertainty in the median. Then a 5th extra data column is expected to contain the number of points in the distribution. -G Select color or pattern for filling of symbols or polygons [Default is no fill]. (See SPECIFYING FILL below). Note when -m is chosen, psxy will search for -G and -W strings in all the subheaders and let any values thus found over-ride the command line settings (see -m below). -H Input file(s) has header record(s). If used, the default number of header records is N_HEADER_RECS. Use -Hi if only input data should have header records [Default will write out header records if the input data have them]. Blank lines and lines starting with # are always skipped. -I Use the supplied intens value (nominally in the -1 to + 1 range) to modulate the fill color by simulating illumination [none]. -K More PostScript code will be appended later [Default terminates the plot system]. -L Force closed polygons: connect the endpoints of the line-segment(s) and draw polygons. Also, in concert with -C, -m, and -Z settings in the headers will use the implied color for polygon fill [Default is polygon pen color]. -N Do NOT skip symbols that fall outside map border [Default plots points inside border only]. The option does not apply to lines and polygons which are always clipped to the map region. -O Selects Overlay plot mode [Default initializes a new plot system]. -P Selects Portrait plotting mode [Default is Landscape, see gmtdefaults to change this]. -S Plot symbols. If present, size is symbol size in the unit set in .gmtdefaults4 (unless c, i, m, or p is appended). If size is not given it is expected in the third (or 4th if -C is used) column. Any additional fields are shifted over by one column. If the symbol code (see below) is not given it will be read from the last column in the input data; this cannot be used in conjunction with -b. Optionally, append c, i, m, p to indicate that the size information in the input data is in units of cm, inch, meter, or point, respectively [Default is MEASURE_UNIT]. Note: if you give both size and symbol via the input file you must use MEASURE_UNIT to indicate the units used for the symbol size. The uppercase symbols A, C, D, G, H, I, N, S, T are normalized to have the same area as a circle with diameter size, while the size of the corresponding lowercase symbols refers to the diameter of a circumscribed circle. Choose between these symbol codes: -S- x-dash (-). size is the length of a short horizontal line segment. -S+ plus (+). size is diameter of circumscribing circle. -Sa star. size is diameter of circumscribing circle. -Sb Vertical bar extending from base to y. size is bar width. Append u if size is in x-units [Default is plot-distance units]. By default, base = ymin. Append bbase to change this value. -SB Horizontal bar extending from base to x. size is bar width. Append u if size is in y-units [Default is plot-distance units]. By default, base = xmin. Append bbase to change this value. -Sc circle. size is diameter of circle. -Sd diamond. size is diameter of circumscribing circle. -Se ellipse. Direction (in degrees counter-clockwise from horizontal), major_axis, and minor_axis must be found in columns 3, 4, and 5. -SE Same as -Se, except azimuth (in degrees east of north) should be given instead of direction. The azimuth will be mapped into an angle based on the chosen map projection (-Se leaves the directions unchanged.) Furthermore, the axes lengths must be given in km instead of plot-distance units. An exception occurs for a linear projection in which we assume the ellipse axes are given in the same units as -R. -Sf front. -Sfgap/size[dir][type][:offset]. Supply distance gap between symbols and symbol size. If gap is negative, it is interpreted to mean the number of symbols along the front instead. Append dir to plot symbols on the left or right side of the front [Default is centered]. Append type to specify which symbol to plot: box, circle, fault, slip, or triangle. [Default is fault]. Slip means left-lateral or right-lateral strike-slip arrows (centered is not an option). Append :offset to offset the first symbol from the beginning of the front by that amount [Default is 0]. -Sg octagon. size is diameter of circumscribing circle. -Sh hexagon. size is diameter of circumscribing circle. -Si inverted triangle. size is diameter of circumscribing circle. -Sj Rotated rectangle. Direction (in degrees counter-clockwise from horizontal), x- dimension, and y-dimension must be found in columns 3, 4, and 5. -SJ Same as -Sj, except azimuth (in degrees east of north) should be given instead of direction. The azimuth will be mapped into an angle based on the chosen map projection (-Sj leaves the directions unchanged.) Furthermore, the dimensions must be given in km instead of plot-distance units. An exception occurs for a linear projection in which we assume the dimensions are given in the same units as -R. -Sk kustom symbol. Append <name>/size, and we will look for a definition file called <name>.def in (1) the current directory or (2) in ~/.gmt or (3) in $GMT_SHAREDIR/custom. The symbol as defined in that file is of size 1.0 by default; the appended size will scale symbol accordingly. Users may add their own custom *.def files; see CUSTOM SYMBOLS below. -Sl letter or text string (less than 64 characters). Give size, and append /string after the size. Note that the size is only approximate; no individual scaling is done for different characters. Remember to escape special characters like *. Optionally, you may append %font to select a particular font [Default is ANNOT_FONT_PRIMARY]. -Sm math angle arc, optionally with one or two arrow heads. The size is the radius of the arc. Start and stop directions (in degrees counter-clockwise from horizontal) for arc must be found in columns 3 and 4. Use -Smf to add arrow head at first angle, -Sml for arrow head at last angle, and -Smb for both [Default is no arrow heads]. -Sn pentagon. size is diameter of circumscribing circle. -Sp point. No size needs to be specified (1 pixel is used). -Sq quoted line, i.e., lines with annotations such as contours. Append [d|D|f|l|L|n|x|X]info[:labelinfo]. The required argument controls the placement of labels along the quoted lines. Choose among five controlling algorithms: ddist[c|i|m|p] or Ddist[d|e|k|m|n] For lower case d, give distances between labels on the plot in your preferred measurement unit c (cm), i (inch), m (meter), or p (points), while for upper case D, specify distances in map units and append the unit; choose among e (m), k (km), m (mile), n (nautical mile), or d (spherical degree). [Default is 10c or 4i]. fffile.d Reads the ascii file ffile.d and places labels at locations in the file that matches locations along the quoted lines. Inexact matches and points outside the region are skipped. l|Lline1[,line2,...] Give start and stop coordinates for one or more comma-separated straight line segments. Labels will be placed where these lines intersect the quoted lines. The format of each line specification is start/stop, where start and stop are either a specified point lon/lat or a 2-character XY key that uses the justification format employed in pstext to indicate a point on the map, given as [LCR][BMT]. L will interpret the point pairs as defining great circles [Default is straight line]. nn_label Specifies the number of equidistant labels for quoted lines line . Upper case N starts labeling exactly at the start of the line [Default centers them along the line]. N-1 places one justified label at start, while N+1 places one justified label at the end of quoted lines. Optionally, append /min_dist[c|i|m|p] to enforce that a minimum distance separation between successive labels is enforced. x|Xxfile.d Reads the multi-segment file xfile.d and places labels at the intersections between the quoted lines and the lines inxfile.d. X will resample the lines first along great-circle arcs. In addition, you may optionally append +rradius[c|i|m|p] to set a minimum label separation in the x-y plane [no limitation]. The optional labelinfo controls the specifics of the label formatting and consists of a concatenated string made up of any of the following control arguments: +aangle For annotations at a fixed angle, +an for line-normal, or +ap for line- parallel [Default]. +cdx[/dy] Sets the clearance between label and optional text box. Append c|i|m|p to specify the unit or % to indicate a percentage of the label font size [15%]. +d Turns on debug which will draw helper points and lines to illustrate the workings of the quoted line setup. +ffont Sets the desired font [Default ANNOT_FONT_PRIMARY]. +g[color] Selects opaque text boxes [Default is transparent]; optionally specify the color [Default is PAGE_COLOR]. (See SPECIFYING COLOR below). +jjust Sets label justification [Default is MC]. Ignored when -SqN|n+|-1 is used. +kcolor Sets color of text labels [Default is COLOR_BACKGROUND]. (See SPECIFYING COLOR below). +llabel Sets the constant label text. +Lflag Sets the label text according to the specified flag: +Lh Take the label from the current multisegment header (first scan for an embedded -Llabel option, if not use the first word following the segment flag). For multiple-word labels, enclose entire label in double quotes. +Ld Take the Cartesian plot distances along the line as the label; append c|i|m|p as the unit [Default is MEASURE_UNIT]. +LD Calculate actual map distances; append d|e|k|m|n as the unit [Default is d(egrees), unless label placement was based on map distances along the lines in which case we use the same unit specified for that algorithm]. Requires a map projection to be used. +Lf Use text after the 2nd column in the fixed label location file as the label. Requires the fixed label location setting. +Lx As +Lh but use the headers in the xfile.d instead. Requires the crossing file option. +ndx[/dy] Nudges the placement of labels by the specified amount (append c|i|m|p to specify the units). Increments are considered in the coordinate system defined by the orientation of the line; use +N to force increments in the plot x/y coordinates system [no nudging]. +o Selects rounded rectangular text box [Default is rectangular]. Not applicable for curved text (+v) and only makes sense for opaque text boxes. +p[pen] Draws the outline of text boxsets [Default is no outline]; optionally specify pen for outline [Default is width = 0.25p, color = black, texture = solid]. (See SPECIFYING PENS below). +rmin_rad Will not place labels where the line's radius of curvature is less than min_rad [Default is 0]. +ssize Sets the desired font size in points [Default is 9]. +uunit Appends unit to all line labels. If unit starts with a leading hyphen (-) then there will be no space between label value and the unit. [Default is no unit]. +v Specifies curved labels following the path [Default is straight labels]. +w Specifies how many (x, y) points will be used to estimate label angles [Default is 10]. +=prefix Prepends prefix to all line labels. If prefix starts with a leading hyphen (-) then there will be no space between label value and the prefix. [Default is no prefix]. -Sr rectangle. No size needs to be specified, but the x- and y-dimensions must be found in columns 3 and 4. -Ss square. size is diameter of circumscribing circle. -St triangle. size is diameter of circumscribing circle. -Sv vector. Direction (in degrees counter-clockwise from horizontal) and length must be found in columns 3 and 4. size, if present, will be interpreted as arrowwidth/headlength/headwidth [Default unit is 0.075c/0.3c/0.25c (or 0.03i/0.12i/0.1i)]. By default arrow attributes remains invariant to the length of the arrow. To have the size of the vector scale down with decreasing size, append nnorm, where vectors shorter than norm will have their attributes scaled by length/norm. To center vector on balance point, use -Svb; to align point with the vector head, use -Svh; to align point with the vector tail, use -Svt [Default]. To give the head point's coordinates instead of direction and length, use -Svs. Upper case B, H, T, S will draw a double-headed vector [Default is single head]. -SV Same as -Sv, except azimuth (in degrees east of north) should be given instead of direction. The azimuth will be mapped into an angle based on the chosen map projection (-Sv leaves the directions unchanged.) -Sw pie wedge. Start and stop directions (in degrees counter-clockwise from horizontal) for pie slice must be found in columns 3 and 4. -SW Same as -Sw, except azimuths (in degrees east of north) should be given instead of the two directions. The azimuths will be mapped into angles based on the chosen map projection (-Sw leaves the directions unchanged.) -Sx cross (x). size is diameter of circumscribing circle. -Sy y-dash (|). size is the length of a short vertical line segment. -T Ignore all input files, including standard input. This is the same as specifying /dev/null (or NUL for Windows users) as input file. Use this to activate only the options that are not related to plotting of lines or symbols, such as psxy -R -J -O -T to terminate a sequence of GMT plotting commands without producing any plotting output. -U Draw Unix System time stamp on plot. By adding just/dx/dy/, the user may specify the justification of the stamp and where the stamp should fall on the page relative to lower left corner of the plot. For example, BL/0/0 will align the lower left corner of the time stamp with the lower left corner of the plot. Optionally, append a label, or c (which will plot the command string.). The GMT parameters UNIX_TIME, UNIX_TIME_POS, and UNIX_TIME_FORMAT can affect the appearance; see the gmtdefaults man page for details. The time string will be in the locale set by the environment variable TZ (generally local time). -V Selects verbose mode, which will send progress reports to stderr [Default runs "silently"]. -W Set pen attributes for lines or the outline of symbols [Defaults: width = 0.25p, color = black, texture = solid]. A leading + will use the lookup color (via -C) for both symbol fill and outline pen color, while a leading - will set outline pen color and turn off symbol fill. (See SPECIFYING PENS below). -X -Y Shift plot origin relative to the current origin by (x-shift,y-shift) and optionally append the length unit (c, i, m, p). You can prepend a to shift the origin back to the original position after plotting, or prepend r [Default] to reset the current origin to the new location. If -O is used then the default (x- shift,y-shift) is (0,0), otherwise it is (r1i, r1i) or (r2.5c, r2.5c). Alternatively, give c to align the center coordinate (x or y) of the plot with the center of the page based on current page size. -: Toggles between (longitude,latitude) and (latitude,longitude) input and/or output. [Default is (longitude,latitude)]. Append i to select input only or o to select output only. [Default affects both]. -bi Selects binary input. Append s for single precision [Default is d (double)]. Uppercase S or D will force byte-swapping. Optionally, append ncol, the number of columns in your binary input file if it exceeds the columns needed by the program. Or append c if the input file is netCDF. Optionally, append var1/var2/... to specify the variables to be read. [Default is the required number of columns given the chosen settings]. -c Specifies the number of plot copies. [Default is 1]. -f Special formatting of input and/or output columns (time or geographical data). Specify i or o to make this apply only to input or output [Default applies to both]. Give one or more columns (or column ranges) separated by commas. Append T (absolute calendar time), t (relative time in chosen TIME_UNIT since TIME_EPOCH), x (longitude), y (latitude), or f (floating point) to each column or column range item. Shorthand -f[i|o]g means -f[i|o]0x,1y (geographic coordinates). -g Examine the spacing between consecutive data points in order to impose breaks in the line. Append x|X or y|Y to define a gap when there is a large enough change in the x or y coordinates, respectively, or d|D for distance gaps; use upper case to calculate gaps from projected coordinates. For gap-testing on other columns use [col]z; if col is not prepended the it defaults to 2 (i.e., 3rd column). Append [+|-]gap and optionally a unit u. Regarding optional signs: -ve means previous minus current column value must exceed |gap to be a gap, +ve means current minus previous column value must exceed gap, and no sign means the absolute value of the difference must exceed gap. For geographic data (x|y|d), the unit u may be meter [Default], kilometer, miles, or nautical miles. For projected data (X|Y|D), choose from inch, centimeter, meter, or points [Default unit set by MEASURE_UNIT]. Note: For x|y|z with time data the unit is instead controlled by TIME_UNIT. Repeat the option to specify multiple criteria, of which any can be met to produce a line break. Issue an additional -ga to indicate that all criteria must be met instead. The -g option is ignored if -S is set. -m Multiple segment file. Segments are separated by a record whose first character is flag [Default is '>']. On these segment header records one or more of the following options can be added: -Gfill Use the new fill and turn filling on -G- Turn filling off -G+ Revert to default fill (none if not set on command line) -Wpen Use the new pen and turn outline on -W- Turn outline off -W+ Revert to default pen (none if not set on command line) -Zzval Obtain fill via cpt lookup using z-value zval -ZNaN Get the NaN color from the cpt file SPECIFYING PENS pen The attributes of lines and symbol outlines as defined by pen is a comma delimetered list of width, color and texture, each of which is optional. width can be indicated as a measure (points, centimeters, inches) or as faint, thin[ner|nest], thick[er|est], fat[ter|test], or obese. color specifies a gray shade or color (see SPECIFYING COLOR below). texture is a combination of dashes `-' and dots `.'. SPECIFYING FILL fill The attribute fill specifies the solid shade or solid color (see SPECIFYING COLOR below) or the pattern used for filling polygons. Patterns are specified as pdpi/pattern, where pattern gives the number of the built-in pattern (1-90) or the name of a Sun 1-, 8-, or 24-bit raster file. The dpi sets the resolution of the image. For 1-bit rasters: use Pdpi/pattern for inverse video, or append :Fcolor[B[color]] to specify fore- and background colors (use color = - for transparency). See GMT Cookbook & Technical Reference Appendix E for information on individual patterns. SPECIFYING COLOR color The color of lines, areas and patterns can be specified by a valid color name; by a gray shade (in the range 0-255); by a decimal color code (r/g/b, each in range 0-255; h-s-v, ranges 0-360, 0-1, 0-1; or c/m/y/k, each in range 0-1); or by a hexadecimal color code (#rrggbb, as used in HTML). See the gmtcolors manpage for more information and a full list of color names.
To plot solid red circles (diameter = 0.25 cm) at the positions listed in the file DSDP.xy on a Mercator map at 5 cm/degree of the area 150E to 154E, 18N to 23N, with tickmarks every 1 degree and gridlines every 15 minutes, use psxy DSDP.xy -R 150/154/18/23 -Jm 5c -Sc0.25c -G red -B 1g15m | lpr To plot the xyz values in the file quakes.xyzm as circles with size given by the magnitude in the 4th column and color based on the depth in the third using the color palette cpt on a linear map, use psxy quakes.xyzm -R 0/1000/0/1000 -JX 6i -Sc -C cpt -B 200 > map.ps To plot the file trench.xy on a Mercator map, with white triangles with sides 0.25 inch on the left side of the line, spaced every 0.8 inch, use psxy trench.xy -R 150/200/20/50 -Jm 0.15i -Sf0.8i/0.1ilt -G white -W -B 10 | lpr br To plot the data in the file misc.d as symbols determined by the code in the last column, and with size given by the magnitude in the 4th column, and color based on the third column via the color palette cpt on a linear map, use psxy misc.d -R 0/100/-50/100 -JX 6i -S -C cpt -B 20 > t.ps
psxy and psxyz allows users to define and plot their own custom symbols. This is done by encoding the symbol using a simple plotting code described below. Put all the plotting codes for your new symbol in a file whose extension must be .def; you may then address the symbol without giving the extension (e.g., the symbol file tsunami.def is used by specifying -Sktsunami/size. The definition file can contain any number of plot code records, as well as blank lines and comment lines (starting with #). psxy and psxyz will look for the definition files in (1) the current directory, (2) the ~/.gmt directory, and (3) the $GMT_SHAREDIR/custom directory, in that order. Freeform polygons (made up of straight line segments and arcs of circles) can be designed - these polygons can be painted and filled with a pattern. Other standard geometric symbols can also be used. Generate freeform polygons by starting with an anchor point (append [ -Wpen ] and [ -Gfill ] to indicate pen and fill attributes): x0 y0 M and draw a straight line from the current point to the next point with x y D or add an arc by using xc yc r dir1 dir2 A When a record other than the D or A is encountered, the polygon is closed and considered complete. The optional pen and fill setting hardwires particular values for this feature. If not present the polygon's characteristics are determined by the command line settings for pen and fill. To deactivate fill or outline for any given polygon, give -G- or -W-. To add other geometric shapes to your custom symbol, add any number of the following plot code records (each accepts the optional [ -Wpen ] and [ -Gfill ] at the end): circle: x y size c cross: x y size x diamond: x y size d ellipse: x y dir major minor e hexagon: x y size h invtriangle: x y size i letter: x y size string l octagon: x y size g pentagon: x y size n plus: x y size + rect: x y xwidth ywidth r square: x y size s star: x y size a triangle: x y size t wedge: x y radius dir1 dir2 w x-dash: x y size - y-dash: x y size y When designing your symbol, the x, y and other dimensions are relative to a symbol of size 1, and all the dimensions will be scaled by the actual symbol size chosen at run-time. To design a symbol, make a grid paper with psbasemap -R-0.5/0.5/-0.5/0.5 -JX 4i -Ba 0.1g0.05 -P > grid.ps and draw your symbol, centering it on (0,0). For examples of symbols, see the set supplied with GMT in $GMT_SHAREDIR/custom.
The -N option does not adjust the BoundingBox information so you may have to post-process the PostScript output with ps2raster -A to obtain the correct BoundingBox. psxy cannot handle filling of polygons that contain the south or north pole. For such a polygon, make a copy and split it into two and make each explicitly contain the polar point. The two polygons will combine to give the desired effect when filled; to draw outline use the original polygon.