CPPKLB - Picks a set of labels for labeled contour levels.

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

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

       #include <ncarg/ncargC.h>

       void c_cppklb (float *zdat, float *rwrk, int *iwrk)

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.

UNIX                                               March 1993                                     CPPKLB(3NCARG)

       All three arguments are arrays used in the last call to CPRECT, CPSPS1, or CPSPS2, the contents of which
       must not have been changed since that call.

       ZDAT        (REAL  array,  dimensioned as specified in the last call to CPRECT, CPSPS1, or CPSPS2, input)
                   is the data array.

       RWRK        (REAL array, dimensioned as specified  in  the  last  call  to  CPRECT,  CPSPS1,  or  CPSPS2,
                   input/output) is the real workspace array.

       IWRK        (INTEGER  array,  dimensioned  as  specified  in  the last call to CPRECT, CPSPS1, or CPSPS2,
                   input/output) is the integer workspace array.

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

       See the conpack man page for a description of all Conpack error messages and/or informational messages.

       CPPKLB - Picks a set of labels for labeled contour levels.

       Online:  conpack, cpback, cpchcf, cpchcl, cpchhl, cpchil, cpchll, cpcica, cpclam, cpcldm, cpcldr, cpcltr,
       cpcnrc, cpdrpl, cpezct, cpgetc, cpgeti, cpgetr, cplbam, cplbdr, cpmpxy, cpmviw, cpmvrw,  cppkcl,  cprect,
       cprset, cpscae, cpsetc, cpseti, cpsetr, cpsps1, cpsps2, ncarg_cbind

       Hardcopy: NCAR Graphics Contouring and Mapping Tutorial

       CALL CPPKLB (ZDAT, RWRK, IWRK)

       Normally, CPPKLB is called by Conpack when labels for the contour levels are needed.  You can call CPPKLB
       directly (after the initialization call to CPRECT,  CPSPS1  or  CPSPS2)  when  you  want  to  modify  the
       resulting parameter arrays that specify the labels.

       If the constant-field-flag 'CFF' is non-zero, indicating that, during the last call to CPRECT, CPSPS1, or
       CPSPS2,  the data were found to be essentially constant, CPPKLB does nothing.  Otherwise, CPPKLB examines
       the first 'NCL' elements of the parameter  array  'CLV',  which  defines  the  contour  levels,  and  the
       associated  parameter  arrays,  looking  for  levels that are to be labeled ('CLU' = 2 or 3) for which no
       label is specified (the associated element of 'LLT' is ' ', a single  blank.)  If  any  such  levels  are
       found, labels are generated for them.

       The  scale  factor  'SFU'  may  be set as a byproduct of choosing the labels.  See the description of the
       parameters 'SFU' (scale factor used) and 'SFS' (scale factor selector) in the conpack_params man page.

       After calling CPPKLB, a user program may examine the generated labels and change them in various ways.