Initialize sphere drawing package. sphinit Keywords: --- Set values: LONG = central longitude (East is +, def=0). LAT = central latitude (def=0). PA = position angle of north pole (def=0). X = X position of sphere center (def=0). Y = Y position of sphere center (def=0). INC = angle increment (def=1). VPA = Position angle of visible hemisphere center (def=0). VAZ = Line of sight ang. of vis. hemisphere center (def=0). VIS_STYLE = def linestyle for sphere visible part (def=0). HID_STYLE = def linestyle for sphere hidden part (def=1). --- Actions: /LIST list values. /FRONT set visible hemisphere to front of sphere. /TOP set visible hemisphere to top of sphere. /DEVICE work in device coordinates. RADIUS = r. Plot outline of radius r. COLOR = c. Outline plot color. FILL = f. Fill color for inside radius (def = no fill). LINESTYLE = s. Outline linestyle. THICK = t. Outline plot thickness.
sphinit gives:
sphinit, long=-30, lat=40 gives:
The last example has a minor problem. The sphere is not outlined
and for this orientation breaks detract from the figure.
sphinit will draw an outline if given the radius by the the
keyword radius. The interior of the sphere may also be
filled by a given color using the keyword fill. The sphere
may also be tilted away from straight up using the keyword pa
to control the position angle of the north pole. Using these
three keywords together:
sphinit, long=-30, lat=40, rad=1, fill=40, pa=30 gives:
Other keywords are available in sphinit, see the built in help.
sphinit may be called any number of times to orient the spherical coordinate system in various ways. Each keyword value stays in effect until a new value is specified, so it is not necessary to give all the keywords on every call, just the ones to change.
The current values in effect for the drawing routines may be listed
by the call:
sphinit,/list