plcont - Contour plot

f (PLFLT_MATRIX(3plplot), input)
              A matrix containing data to be contoured.

       nx,ny (PLINT(3plplot), input)
              The dimensions of the matrix f.

       kx,lx (PLINT(3plplot), input)
              Range of x indices to consider where 0 <= kx-1 < lx-1 < nx.  Values of kx  and  lx  are  one-based
              rather than zero-based for historical backwards-compatibility reasons.

       ky,ly (PLINT(3plplot), input)
              Range  of  y  indices  to consider where 0 <= ky-1 < ly-1 < ny.  Values of ky and ly are one-based
              rather than zero-based for historical backwards-compatibility reasons.

       clevel (PLFLT_VECTOR(3plplot), input)
              A vector specifying the levels at which to draw contours.

       nlevel (PLINT(3plplot), input)
              Number of contour levels to draw.

       pltr (PLTRANSFORM_callback(3plplot), input)
              A callback function that defines the transformation between the zero-based indices of the matrix f
              and the 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.

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

       Draws  a contour plot of the data in f[nx][ny], using the nlevel contour levels specified by clevel. Only
       the region of the matrix from kx to lx and from ky to ly is plotted out where all these index ranges  are
       interpreted  as  one-based  for  historical  reasons.  A transformation routine pointed to by pltr with a
       generic pointer pltr_data for additional data required by the  transformation  routine  is  used  to  map
       indices within the matrix to the world coordinates.

       Redacted  form: plcont(f,kx,lx,ky,ly,clevel,pltr,pltr_data) where (see above discussion) the pltr,
       pltr_data callback arguments are sometimes replaced by a tr vector with 6 elements; xg and yg vectors; or
       xg and yg matrices.

       This function is used in examples 9, 14, 16, and 22.

plcont - Contour plot

       PLplot documentation at http://plplot.org/documentation.php.

                                                   July, 2025                                    PLCONT(3plplot)

plcont(f, nx, ny, kx, lx, ky, ly, clevel, nlevel, pltr, pltr_data)