NAME

       PWRZT - Draws the projections of character strings that are positioned in a plane parallel
       to one of the three coordinate planes.

       NOTE: At one time, a Threed routine called PSYM3 was supported.  It has long been
       considered obsolete.  If you call PSYM3, you will get an error message telling you to use
       PWRZT instead and execution will be terminated.

       As nearly as we can determine, the statement

             CALL PSYM3 (U,V,W,ICHAR,ISIZE,IDIR,ITOP,IUP)

       may be replaced by the statements

             IF (IUP.EQ.2) CALL VECT3 (U,V,W)
             CALL PWRZT (U,V,W,ICHAR,1,ISIZE,IDIR,ITOP,0)

       (Old manuals seem to indicate that the fifth argument in the call to PSYM3 may have been a
       real called SIZE, rather than an integer called ISIZE; it is not clear whether this was a
       misprint or not.)

       The function of PSYM3 was to plot a symbol at the projection of a particular point; this
       can now be done with PWRZT.  If the eighth argument in the second and following of a
       series of calls to PSYM3 had the value 2, straight-line segments were drawn connecting the
       projections of the points; this is better done with a single call to CURVE3, or by calling
       FRST3 for the first point and VECT3 for each of the other points.

SYNOPSIS

       CALL PWRZT (U,V,W,CHRS,LCHRS,ISIZE,IDIR,ITOP,ICEN)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_pwrzt (float u, float v, float w, char *chrs, int lchrs,
       int isize, int idir, int itop, int icen)

DESCRIPTION

       U,V,W       (input expressions of type REAL) are the U, V, and W coordinates of a point,
                   in the user's 3-space, relative to which the character string is to be
                   positioned.

       CHRS        (an input constant or variable of type CHARACTER) is the character string to
                   be drawn.  It may contain uppercase alphabetic characters, the digits 0
                   through 9, and a small set of "special" characters (plus, minus, asterisk,
                   slash, left and right parentheses, equals sign, blank, comma, and period).
                   Other characters are treated as blanks.  (Note especially that lowercase
                   alphabetic characters are not available.)

       LCHRS       (an input expression of type INTEGER) is the number of characters in CHRS.

       ISIZE       (an input expression of type INTEGER) specifies the character width to be
                   used, defined in terms of the width of the plotter frame.  Because projected
                   characters vary in width depending on just where they are placed within the
                   box being viewed and the position from which that box is viewed, ISIZE is
                   interpreted as specifying the width of a character when that character is
                   positioned and viewed in such a way as to make it as large as it could
                   possibly be - when the character is on the near side of the box and in a plane
                   perpendicular to the line of sight.  Specifically,

                       If between 0 and 3, ISIZE is 1., 1.5, 2., or 3. times a standard width
                       equal to 1/128th of the screen width.

                       If greater than 3, ISIZE is the character width in units of 1/1024th of
                       the plotter frame.

                   One third of the "width" referred to here is white space.  What ISIZE really
                   specifies is the distance between the centers of adjacent characters in a
                   string.  Characters are digitized to be 7/6 * ISIZE units high and 4/6 * ISIZE
                   units wide, excluding white space.

       IDIR        (an input expression of type INTEGER) is the direction in which the character
                   string is to be written, as follows:

                       1 = +U    -1 = -U

                       2 = +V    -2 = -V

                       3 = +W    -3 = -W

       ITOP        (an input expression of type INTEGER) is the direction from the center of the
                   first character to the top of the first character; possible values of ITOP are
                   the same as those of IDIR, above.  ABS(ITOP) must not be equal to ABS(IDIR).

       ICEN        (an input expression of type INTEGER) is the centering option, specifying
                   where (U,V,W) is relative to the string written, as follows:

                   -1  (U,V,W) is the center of the left edge of the first character.

                    0  (U,V,W) is the center of the entire string.

                    1  (U,V,W) is the center of the right edge of the last character.

       Because characters drawn by PWRZT are stroked using the GKS polyline primitive (so that
       they can be projected from 3-D to 2-D), they are drawn in the current polyline color, as
       determined by the last call to the GKS routine GSPLCI; by default, color index 1 is used.
       Line width is determined by the last call to the GKS routine GSLWSC; by default, the line
       width scale factor is 1.

C-BINDING DESCRIPTION

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions.

EXAMPLES

       Use the ncargex command to see the following relevant example: tpwrzt.

ACCESS

       To use PWRZT or c_pwrzt, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c,
       preferably in that order.

SEE ALSO

       Online: threed, curve3, fence3, frst3, line3, perim3, point3, psym3, pwrz, set3, threed,
       tick3, tick43, vect3, ncarg_cbind.

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.