1c_shgrid(3NCARG)                 NCAR GRAPHICS                c_shgrid(3NCARG)
2
3
4

NAME

6       c_shgrid  -  interpolate  random data in 3-space using a modified Shep‐
7       ard's algorithm
8

FUNCTION PROTOTYPE

10       float *c_shgrid(int, float [], float [], float [], float [],
11                       int, int, int, float [], float [], float [], int*);
12
13

SYNOPSIS

15       float *c_shgrid (n, x[], y[], z[], f[], nxo, nyo, nzo,
16                        xo[], yo[], zo[], ier);
17
18

DESCRIPTION

20       n           (integer,input) The number of input data points (n > 9).
21
22       xi          (float, input) An array dimensioned for n containing the  X
23                   coordinate values for the input function.
24
25       yi          (float,  input) An array dimensioned for n containing the Y
26                   coordinate values for the input function.
27
28       zi          (float, input) An array dimensioned for n containing the  Z
29                   coordinate values for the input function.
30
31       f           (float, input) An array containing the functional values of
32                   the input function --  f[k]  is  the  functional  value  at
33                   (xi[k], yi[k], zi[k]) for k=0,n-1.
34
35       nxo         (integer,  input)  The  number of X coordinate values to be
36                   calculated for the output grid.
37
38       nyo         (integer, input) The number of Y coordinate  values  to  be
39                   calculated for the output grid.
40
41       nzo         The  number of Z coordinate values to be calculated for the
42                   output grid.
43
44       xo          (float, input) An array dimensioned for nxo containing  the
45                   X coordinates of the output grid.
46
47       yo          (float, output) An array dimensioned for nyo containing the
48                   Y coordinates of the output grid.
49
50       zo          (float, output) An array dimensioned for nzo containing the
51                   Z coordinates of the output grid.
52
53       ier         (pointer  to  integer,  output)  An error return value.  If
54                   *ier is returned as 0, then no  errors  were  detected.  If
55                   *ier is non-zero, then refer to the error list in the error
56                   table for details.
57

USAGE

59       c_shgrid is called to interpolate  randomly  spaced  data  in  3-space.
60       c_shgrid uses a modified Shepard's algorithm to construct an interpola‐
61       tory surface.
62
63       c_shgrid returns a pointer to a linear array of data that is the inter‐
64       polation grid stored in row-major order. That is, if out is declared as
65
66         float *out;
67
68       and we set:
69
70         out = c_shgrid(n, x, y, z, f, nxo, nyo, nzo, xo, yo, zo, ier);
71
72       then  out[nz*ny*i  +  nz*j  + k] is the approximation function value at
73       coordinate point (xo[i], yo[j], zo[k]) for 0 <= i < nx, 0 <=  j  <  ny,
74       and  0  <=  k < nz. The space for out is allocated internal to c_shgrid
75       and is nx*ny*nz floats in size.
76

ACCESS

78       To use c_shgrid, load the NCAR Graphics library ngmath.
79

SEE ALSO

81       shgrid_params, c_shseti, c_shgeti, c_shgetnp.
82
83       Complete documentation for Shgrid is available at URL
84       http://ngwww.ucar.edu/ngdoc/ng/ngmath/shgrid/shhome.html
85
87       Copyright (C) 1997-2000
88       University Corporation for Atmospheric Research
89
90       The use of this Software is governed by a License Agreement.
91
92
93
94UNIX                            September 1999                c_shgrid(3NCARG)
Impressum