NAME

       plvect - Vector plot

SYNOPSIS

       plvect(u, v, nx, ny, scale, pltr, pltr_data)

DESCRIPTION

       Draws  a plot of vector data contained in the matrices (u[nx][ny],v[nx][ny]) . The scaling factor for the
       vectors is given by scale. A transformation routine pointed to by  pltr  with  a  pointer  pltr_data  for
       additional  data  required  by the transformation routine to map indices within the matrices to the world
       coordinates. The style of the vector arrow may be set using plsvect(3plplot).

       Redacted form: plvect(u, v, scale, pltr, pltr_data) where (see  above  discussion)  the  pltr,  pltr_data
       callback  arguments  are  sometimes replaced by a tr vector with 6 elements, or xg and yg array arguments
       with either one or two dimensions.

       This function is used in example 22.

ARGUMENTS

       u, v (PLFLT_MATRIX(3plplot), input)
              A pair of matrices containing the x and y components of the vector data to be plotted.

       nx, ny (PLINT(3plplot), input)
              Dimensions of the matrices u and v.

       scale (PLFLT(3plplot), input)
              Parameter to control the scaling factor of the vectors for  plotting.  If  scale  =  0   then  the
              scaling  factor  is automatically calculated for the data. If scale < 0 then the scaling factor is
              automatically calculated for the data and then multiplied by -scale. If scale > 0 then the scaling
              factor is set to scale.

       pltr (PLTRANSFORM_callback(3plplot), input)
              A callback function that defines the transformation between the zero-based indices of the matrices
              u and v and world coordinates.For the C case, transformation functions are provided in the  PLplot
              library:  pltr0(3plplot)  for  the  identity  mapping,  and  pltr1(3plplot) and pltr2(3plplot) for
              arbitrary mappings respectively defined by vectors and matrices.  In addition, C callback routines
              for  the  transformation  can  be  supplied  by  the  user  such  as  the   mypltr   function   in
              examples/c/x09c.c  which  provides  a  general linear transformation between index coordinates and
              world coordinates.For languages other than C you should consult the PLplot documentation  for  the
              details  concerning  how  PLTRANSFORM_callback(3plplot)  arguments  are  interfaced.  However,  in
              general, a particular pattern of  callback-associated  arguments  such  as  a  tr  vector  with  6
              elements;  xg  and  yg  vectors;  or  xg  and yg matrices are respectively interfaced to a linear-
              transformation routine similar to the above mypltr function; pltr1(3plplot);  and  pltr2(3plplot).
              Furthermore, some of our more sophisticated bindings (see, e.g., the PLplot documentation) support
              native  language  callbacks  for  handling index to world-coordinate transformations.  Examples of
              these  various  approaches  are   given   in   examples/<language>x09*,   examples/<language>x16*,
              examples/<language>x20*,   examples/<language>x21*,   and  examples/<language>x22*,  for  all  our
              supported languages.

       pltr_data (PLPointer(3plplot), input)
              Extra parameter to help pass information to  pltr0(3plplot),  pltr1(3plplot),  pltr2(3plplot),  or
              whatever callback routine that is externally supplied.

AUTHORS

       Many  developers  (who  are  credited  at  http://plplot.sourceforge.net/credits.php) have contributed to
       PLplot over its long history.

SEE ALSO

       PLplot documentation at http://plplot.sourceforge.net/documentation.php.

                                                 November, 2017                                  PLVECT(3plplot)