psvelo - Plot velocity vectors, crosses, and wedges on maps
psvelo [ table ] -Jparameters -R[unit]xmin/xmax/ymin/ymax[r] [ -Aparameters ] [ -B[p|s]parameters ] [ -Fcolor ] [ -Ecolor ] [ -Gfill ] [ -K ] [ -L ] [ -N ] [ -O ] [ -P ] [ -Ssymbol/scale/conf/font_size ] [ [ -U[just/dx/dy/][c|label] ] [ -V[level] ] [ -Wpen ] [ -X[a|c|f|r][x-shift[u]] ] [ -Y[a|c|f|r][y-shift[u]] ] [ -ccopies ] [ -h[i|o][n][+c][+d][+rremark][+rtitle] ] [ -icols[l][sscale][ooffset][,...] ] [ -:[i|o] ]
Note: No space is allowed between the option flag and the associated arguments.
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 It has been replaced by psvelo and psmeca.
-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.
-X[a|c|f|r][x-shift[u]]
Several modifiers may be appended to the vector-producing options to specify the placement of vector heads, their shapes, and the justification of the vector:
+aangle sets the angle of the vector head apex [30].
+b places a vector head at the beginning of the vector path [none].
+e places a vector head at the end of the vector path [none].
+g-|fill turns off vector head fill (if -) or sets the vector head fill [Default fill is used, which may be no fill].
+l draws half-arrows, using only the left side [both].
+nnorm scales down vector attributes (pen thickness, head size) with decreasing length, where vectors shorter than norm will have their attributes scaled by length/norm [arrow attributes remains invariant to length].
+oplon/plat specifies the oblique pole for the great or small circles. Only needed for great circles if +q is given.
+p[-][pen] sets the vector pen attributes. If pen has a leading - then the head outline is not drawn. [Default pen is used, and head outline is drawn]
+q means the input angle, length is instead the start and stop opening angles of the arc segment relative to the point.
+r draws half-arrows, using only the right side [both].
In addition, all but circular vectors may take these modifiers:
+jjust determines how the input x,y point relates to the vector. Choose from beginning [default], end, or center.
+s means the input angle, length is instead the x, y coordinates of the vector end point.
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.
gmt psvelo << END -h2 -R-10/10/-10/10 -W0.25p,red -Ggreen -L -Se0.2/0.39/18 \ -B1g1 -Jx0.4/0.4 -A0.3p -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.
gmt psvelo << END -Sw0.4/1.e7 -W0.75p -Gdarkgray -Elightgray -h1 -D2 -Jm2.2 \ -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
Bomford, G., Geodesy, 4th ed., Oxford University Press, 1980.
Kurt L. Feigl, Department of Geology and Geophysics at University of Wisconsin-Madison, Madison, Wisconsin, USA
Genevieve Patau, Laboratory of Seismogenesis, Institut de Physique du Globe de Paris, Departement de Sismologie, Paris, France