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       has been replaced by psvelo and psmeca.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)

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