## NAME

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

## SYNOPSIS

           psvelo  files   -Jparameters   -Rwest/east/south/north   [
           -Btickinfo  ]  [  -Dsigma_scale  ]  [ -Fred/green/blue ] [
           -Ered/green/blue ] [ -Gfill ] [ -H ] [ -K ] [ -L ] [ -N  ]
           [  -O  ]  [  -P  ]  [  -Ssymbol/scale/conf/font_size  ]  [
           -U[/dx/dy/][label] ] [ -V ] [ -Wpen ] [ -Xx-shift ] [ -Yy-
           shift ] [ -: ] [ -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  out
           put. 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           has been replaced by psvelo and psmeca.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 MEA
                  SURE_UNIT setting in .gmtdefaults, but this can  be
                  overridden  on the command line by appending the c,
                  i, or m to the scale/width value.

                  CYLINDRICAL PROJECTIONS:

                  -Jclon0/lat0/scale (Cassini)
                  -Jjlon0/scale (Miller)
                  -Jmscale (Mercator - Greenwich and Equator as  ori
                  gin)
                  -Jmlon0/lat0/scale  (Mercator  -  Give meridian and
                  standard parallel)
                  -Joalon0/lat0/azimuth/scale  (Oblique  Mercator   -
                  point and azimuth)
                  -Joblon0/lat0/lon1/lat1/scale  (Oblique  Mercator -
                  two points)
                  -Joclon0/lat0/lonp/latp/scale (Oblique  Mercator  -
                  point and pole)
                  -Jqlon0/scale  (Equidistant  Cylindrical Projection
                  (Plate Carree))
                  -Jtlon0/scale (TM - Transverse Mercator, with Equa
                  tor as y = 0)
                  -Jtlon0/lat0/scale  (TM  - Transverse Mercator, set
                  origin)
                  -Juzone/scale (UTM - Universal Transverse Mercator)
                  -Jylon0/lats/scale (Basic Cylindrical Projection)

                  AZIMUTHAL PROJECTIONS:

                  -Jalon0/lat0/scale (Lambert).
                  -Jelon0/lat0/scale (Equidistant).
                  -Jflon0/lat0/horizon/scale (Gnomonic).
                  -Jglon0/lat0/scale (Orthographic).
                  -Jslon0/lat0/[slat/]scale (General Stereographic)

                  CONIC PROJECTIONS:

                  -Jblon0/lat0/lat1/lat2/scale (Albers)
                  -Jdlon0/lat0/lat1/lat2/scale (Equidistant)
                  -Jllon0/lat0/lat1/lat2/scale (Lambert)

                  MISCELLANEOUS PROJECTIONS:

                  -Jhlon0/scale (Hammer)
                  -Jilon0/scale (Sinusoidal)
                  -Jk[f|s]lon0/scale (Eckert IV (f) and VI (s))
                  -Jnlon0/scale (Robinson)
                  -Jrlon0/scale (Winkel Tripel)
                  -Jvlon0/scale (Van der Grinten)
                  -Jwlon0/scale (Mollweide)

                  NON-GEOGRAPHICAL PROJECTIONS:

                  -Jp[a]scale[/origin]  (polar (theta,r) coordinates,
                  optional a for azimuths and offset theta [0])
                  -Jxx-scale[l|ppow][/y-scale[l|ppow]] (Linear,  log,
                  and power scaling)
                  More  details  can  be  found in the psbasemap man
                  pages.

           -R     west, east, south, and north specify the Region  of
                  interest. To specify boundaries in degrees and min
                  utes [and  seconds],  use  the  dd:mm[:ss]  format.
                  Append  r if lower left and upper right map coordi
                  nates are given instead  of  wesn.   -SSelects  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% confi
                  dence 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  inter
                  changes order)

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

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

           7      correlation  between  eastward and northward compo
                  nents

           8      name of station (optional). The  bug  which  previ
                  ously  wrote  a garbage string if this argument was
                  omitted has been fixed.

           -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 inter
                  changes 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 trans
                  parent]. The arrow and  the  circumference  of  the
                  ellipse will be drawn with the pen attributes spec
                  ified by the -W option.  Parameters are expected to
                  be in the following columns:

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

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

           5,6    semi-major, semi-minor axes

           7      counter-clockwise  angle, in degrees, from horizon
                  tal 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 mul
                  tiplied 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.  Param
                  eters are expected to be in the following columns:

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

           3      rotation in radians

           4      rotation uncertainty in radians

           -Sxcross_scale  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  inter
                  changes 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 argu
           ments.

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

           -B     Sets map boundary tickmark intervals. See psbasemap
                  for details.

           -C     Offset focal mechanisms to the latitude and  longi
                  tude specified in the last two columns of the input
                  file.

           -D     Sigma_scale can be used to rescale  the  uncertain
                  ties  of  velocities  (-Se  and  -Sr) and rotations
                  (-Sw). Can be combined with the  confidence   vari
                  able.

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

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

           -Gfill Select filling of ellipses, wedges, and focal mech
                  anisms. By convention, the compressional  quadrants
                  of  the focal mechanism beach balls are shaded. 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
                  (1-32) 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 pspat
                  terns for information on individual patterns.

           -H     Input  file(s)  has  Header  record(s).  Number  of
                  header records can be changed by editing your .gmt
                  defaults file. If used, GMT  default  is  1  header
                  record.

           -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  [GMT  Default is
                  Landscape, see gmtdefaults to change this].

           -U     Draw Unix System time stamp on plot. User may spec
                  ify where the lower left corner of the stamp should
                  fall on the page relative to lower left  corner  of
                  plot.  Optionally, append a label, or c (which will
                  plot  the  command  string.).  The  GMT  parameters
                  UNIX_TIME  and UNIX_TIME_POS can affect the appear
                  ance; see the gmtdefaults man page for details.

           -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 origin of plot by (x-shift,y-shift).  Prepend
                  a for absolute coordinates; the  default  (r)  will
                  reset plot origin.

           -:     Toggles  between  (longitude,latitude)  and  (lati
                  tude,longitude) input/output. [Default  is  (longi
                  tude,latitude)].  Applies to geographic coordinates
                  only.

           -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  -H2   -R-10/10/-10/10   -W1/255/0/0   .br
           -G0/255/0   -L   -Se0.2/0.39/18   -B1g1   -Jx0.4/0.4   .br
           -A0.1/0.3/0.3 -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
           The 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 -Sw0.4/1.e7 -W3 -G60 -E210 -H1 -D2 -Jm2.2 .br
           -R240./243./32.5/34.75 -Bf10ma60m/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(l), psbasemap(l) psxy(l)

## 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)

                                1 Feb 2002                  PSVELO(l)