1CPCLTR(3NCARG)                   NCAR GRAPHICS                  CPCLTR(3NCARG)
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NAME

6       CPCLTR - Traces the contour lines at a given level and retrieves them
7       for some sort of user-defined processing.
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SYNOPSIS

10       CALL CPCLTR (ZDAT,RWRK,IWRK,CLVL,IJMP,IRW1,IRW2,NRWK)
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C-BINDING SYNOPSIS

13       #include <ncarg/ncargC.h>
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15       void c_cpcltr (float *zdat, float *rwrk, int *iwrk,
16       float clvl, int *ijmp, int *irw1, int *irw2, int *nrwk)
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DESCRIPTION

19       The first three arguments are arrays used in the last call to CPRECT,
20       CPSPS1, or CPSPS2, the contents of which must not have been changed
21       since that call.
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23       ZDAT        (REAL array, dimensioned as specified in the last call to
24                   CPRECT, CPSPS1, or CPSPS2, input) is the data array.
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26       RWRK        (REAL array, dimensioned as specified in the last call to
27                   CPRECT, CPSPS1, or CPSPS2, input/output) is the real
28                   workspace array.
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30       IWRK        (INTEGER array, dimensioned as specified in the last call
31                   to CPRECT, CPSPS1, or CPSPS2, input/output) is the integer
32                   workspace array.
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34       CLEV        (REAL, input) is the desired contour level.
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36       IJMP        (INTEGER, input/output) is initially set to zero by the
37                   user. Upon return from CPCLTR, it will be non-zero if
38                   coordinates of a contour line segment have been placed in
39                   RWRK; it will be zero if all contour line segments at the
40                   given level have been generated.
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42       IRW1        (INTEGER, output) is a pointer to the place in RWRK where X
43                   coordinates have been stored. They will be in RWRK(IRW1+I)
44                   for I = 1, 2, ..., NRWK.
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46       IRW2        (INTEGER, output) is a pointer to the place in RWRK where Y
47                   coordinates have been stored. They will be in RWRK(IRW2+I)
48                   for I = 1, 2, ..., NRWK.
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50       NRWK        (INTEGER, output) is the number of points on the contour
51                   line segment. The points comprising the segment will be
52                   (RWRK(IRW1+I),RWRK(IRW2+I)) for I = 1, 2, ... NRWK.
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C-BINDING DESCRIPTION

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

59       The routine CPCLTR may be called at any time after the initialization
60       call to CPRECT, CPSPS1, or CPSPS2.  It is called using code like the
61       following:
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63             IJMP=0
64         101 CALL CPCLTR (ZDAT,RWRK,IWRK,CLEV,IJMP,IRW1,IRW2,NRWK)
65             IF (IJMP.NE.0) THEN
66              (PROCESS SEGMENT OF CONTOUR LINE FROM RWRK)
67              GO TO 101
68             END IF
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70       CPCLTR is called repeatedly.  Initially, IJMP is zeroed.  Upon each
71       return from CPCLTR, if the value of IJMP is non-zero, X and Y
72       coordinates have been placed in the real workspace array RWRK and the
73       values of IRW1, IRW2, and NRWK have been set to indicate where the
74       coordinates were put.  After the coordinates have been processed,
75       CPCLTR is called again.  If, upon return from CPCLTR, the value of IJMP
76       is zero, all contour lines at the specified level have been processed.
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78       If the parameter 'T2D' has a non-zero value, the contour lines are
79       smoothed, using cubic splines under tension.
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ACCESS

82       To use CPCLTR or c_cpcltr, load the NCAR Graphics libraries ncarg,
83       ncarg_gks, and ncarg_c, preferably in that order.
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MESSAGES

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

90       Online: conpack, cpback, cpchcf, cpchcl, cpchhl, cpchil, cpchll,
91       cpcica, cpclam, cpcldm, cpcldr, cpcnrc, cpdrpl, cpezct, cpgetc, cpgeti,
92       cpgetr, cplbam, cplbdr, cpmpxy, cpmviw, cpmvrw, cppkcl, cppklb, cprect,
93       cprset, cpscae, cpsetc, cpseti, cpsetr, cpsps1, cpsps2, ncarg_cbind
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96       Copyright (C) 1987-2009
97       University Corporation for Atmospheric Research
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99       The use of this Software is governed by a License Agreement.
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103UNIX                              March 1993                    CPCLTR(3NCARG)
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