PSVELO(1)

NAME
psvelo - Plot velocity vectors, crosses, and wedges on maps

SYNOPSIS
psvelo files -Jparameters -Rwest/east/south/north[r] [ -AArrow_width/Head_length/Head_width ] [ -B[p|s]parameters ] [ -Dsigma_scale ] [ -Fcolor ] [ -Ecolor ] [ -Gfill ] [ -H[i][nrec] ] [ -K ] [ -L ] [ -N ] [ -O ] [ -P ] [ -Ssymbol/scale/conf/font_size ] [ -U[just/dx/dy/][c|label] ] [ -V ] [ -Wpen ] [ -X[a|c|r][x-shift[u]] ] [ -Y[a|c|r][y-shift[u]] ] [ -:[i|o] ] [ -ccopies ]

DESCRIPTION
psvelo reads data values from files [or standard input] and generates PostScript code that will plot velocity arrows on a map. Most options are the same as for psxy, except -S. The PostScript code is written to standard output. The previous version (psvelomeca) is now obsolete. It has been replaced by psvelo and psmeca.

ARGUMENTS
files List one or more file-names. If no files are given, psvelo will read standard input.

-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  west, east, south, and north specify the Region of interest, 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.

    -S Selects the meaning of the columns in the data file and the figure to be plotted.

-Sevelscale/confidence/fontsize.
    Velocity ellipses in (N,E) convention. Vscale sets the scaling of the velocity arrows. This scaling gives inches (unless c, i, m, or p is appended). Confidence sets the 2-dimensional confidence limit for the ellipse, e.g., 0.95 for 95% confidence ellipse. Fontsize sets the size of the text in points. The ellipse will be filled with the color or shade specified by the -G option [default transparent]. The arrow and the circumference of the ellipse will be drawn with the pen attributes specified by the -W option. Parameters are expected to be in the following columns:

1,2 longitude, latitude of station (-: option interchanges order)

3,4 eastward, northward velocity (-: option interchanges order)

5,6 uncertainty of eastward, northward velocities (1-sigma) (-: option interchanges order)

7   correlation between eastward and northward components

8   name of station (optional).

-Snbarscale.
    Anisotropy bars. Barscale sets the scaling of the bars This scaling gives inches (unless c, i, m, or p is appended). Parameters are expected to be in the following columns:

1,2 longitude, latitude of station (-: option interchanges order)

3,4 eastward, northward components of anisotropy vector (-: option interchanges order)

-Srvelscale/confidence/fontsize
    Velocity ellipses in rotated convention. Vscale sets the scaling of the velocity arrows. This scaling gives inches (unless c, i, m, or p is appended). Confidence sets the 2-dimensional confidence limit for the ellipse, e.g., 0.95 for 95% confidence ellipse. Fontsize sets the size of the text in points. The ellipse will be filled with the color or shade specified by the -G option [default transparent]. The arrow and the circumference of the ellipse will be drawn with the pen attributes specified by the -W option. Parameters are expected to be in the following columns:

1,2 longitude, latitude, of station (-: option interchanges order)

3,4 eastward, northward velocity (-: option interchanges order)

5,6 semi-major, semi-minor axes

7   counter-clockwise angle, in degrees, from horizontal axis to major axis of ellipse.

8   name of station (optional)

-Swwedge_scale/wedge_mag.
    Rotational wedges. Wedge_scale sets the size of the wedges in inches (unless c, i, m, or p is appended). Values are multiplied by Wedge_mag before plotting. For example, setting Wedge_mag to 1.e7 works well for rotations of the order of 100 nanoradians/yr. Use -G to set the fill color or shade for the wedge, and -E to set the color or shade for the uncertainty. Parameters are expected to be in the following columns:

1,2 longitude, latitude, of station (-: option interchanges order)

3   rotation in radians

4   rotation uncertainty in radians

-Sxcross_scale
    gives Strain crosses. Cross_scale sets the size of the cross in inches (unless c, i, m, or p is appended). Parameters are expected to be in the following columns:

1,2 longitude, latitude, of station (-: option interchanges order)

3   eps1, the most extensional eigenvalue of strain tensor, with extension taken positive.

4   eps2, the most compressional eigenvalue of strain tensor, with extension taken positive.

5   azimuth of eps2 in degrees CW from North.

OPTIONS
No space between the option flag and the associated arguments.

-A  Arrow_width/Head_length/Head_width Size of arrow in inches. [Default is 0.03/0.12/0.09].

-B  Sets map boundary annotation and tickmark intervals; see the psbasemap man page for all the details.

-D  Sigma_scale can be used to rescale the uncertainties of velocities (-Se and -Sr) and rotations (-Sw). Can be combined with the confidence variable.

-Ffill
    Sets the color or shade used for frame and annotation. [Default is 0/0/0 (black)]

-Efill
    Sets the color or shade used for filling uncertainty wedges (-Sw) or velocity error ellipses (-Se or -Sr). [If -E is not specified, the uncertainty regions will be transparent.]

-Gfill
    Specify color (for symbols/polygons) or pattern (for polygons). Set the shade (0-255) or color (r/g/b) [Default is 0/0/0]. Optionally, specify -Gpicon_size/pattern, where pattern gives the number of the image pattern (1-90) OR the name of a icon-format file. icon_size sets the unit size in inches. To invert black and white pixels, use -GP instead of -Gp. See pspatterns for information on individual patterns.

-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.

-K  More PostScript code will be appended later [Default terminates the plot system].

-L  Draw lines. Ellipses and fault planes will have their outlines drawn using current pen (see -W).

-N  Do NOT skip symbols that fall outside the frame boundary specified by -R.
     [Default plots symbols inside frame only].

-O  Selects Overlay plot mode [Default initializes a new plot system].

-P  Selects Portrait plotting mode [Default is Landscape, see gmtdefaults to change this].

-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 velocity arrows, ellipse circumference and fault plane edges.
     [Defaults: width = 1, color = 0/0/0, texture = solid].

-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].

-c  Specifies the number of plot copies. [Default is 1].

EXAMPLES

The following should make big red arrows with green ellipses, outlined in red. Note that the 39% confidence scaling will give an ellipse which fits inside a rectangle of dimension Esig by Nsig.

psvelo << END -H 2 -R-10/10/-10/10 -W 0.25p,red -G green -L -Se 0.2/0.39/18 -B 1g1 -Jx 0.4/0.4 -A 0.1/0.3/0.3 -P -V >! test.ps
  Long. Lat. Evel Nvel Esig Nsig CorEN SITE
  (deg) (deg) (mm/yr) (mm/yr)
   0. -8. 0.0 0.0 4.0 6.0 0.500 4x6
  -8. 5. 3.0 3.0 0.0 0.0 0.500 3x3
   0. 0. 4.0 6.0 4.0 6.0 0.500
  -5. -5. 6.0 4.0 6.0 4.0 0.500 6x4
   5. 0. -6.0 4.0 6.0 4.0 -0.500 -6x4
   0. -5. 6.0 -4.0 6.0 4.0 -0.500 6x-4
END
This example should plot some residual rates of rotation in the Western Transverse Ranges, California. The wedges will be dark gray, with light gray wedges to represent the 2-sigma uncertainties.

psvelo <<END -Sw 0.4/1.e7 -W 0.75p -G darkgray -E lightgray -H 1 -D 2 -Jm 2.2 -R 240./243./32.5/34.75 -B f10ma60m/WeSn -P >! test.ps
 lon lat spin(rad/yr) spin_sigma (rad/yr)
241.4806 34.2073 5.65E-08 1.17E-08
241.6024 34.4468 -4.85E-08 1.85E-08
241.0952 34.4079 4.46E-09 3.07E-08
241.2542 34.2581 1.28E-07 1.59E-08
242.0593 34.0773 -6.62E-08 1.74E-08
241.0553 34.5369 -2.38E-07 4.27E-08
241.1993 33.1894 -2.99E-10 7.64E-09
241.1084 34.2565 2.17E-08 3.53E-08
END

SEE ALSO
GMT(1), psbasemap(1), psxy(1)

REFERENCES
Bomford, G., Geodesy, 4th ed., Oxford University Press, 1980.

AUTHORS
Kurt Feigl
CNRS UMR 5562
Toulouse, France
(Kurt.Feigl@.cnes.fr)
Genevieve Patau
CNRS UMR 7580
Seismology Dept.
Institut de Physique du Globe de Paris
(patau@ipgp.jussieu.fr)