1NGRITD(3NCARG) NCAR GRAPHICS NGRITD(3NCARG)
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6 NGRITD - Given the coordinates of a point, this routine performs a
7 rotation of that point about a specified axis by a specified angle.
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10 CALL NGRITD (IAXS,ANGL,UCRD,VCRD,WCRD)
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13 #include <ncarg/ncargC.h>
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15 void c_ngritd(int iaxs, float angl, float *ucrd, float *ycrd,
16 float *wcrd)
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19 IAXS (an input expression of type INTEGER) specifies the axis
20 about which rotation is to be done (1 for the U axis, 2 for
21 the V axis, and 3 for the W axis).
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23 ANGL (an input expression of type REAL) specifies the magnitude,
24 in degrees, of the rotation angle.
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26 UCRD (an input/output variable of type REAL) specifies the U
27 coordinate of the point being rotated.
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29 VCRD (an input/output variable of type REAL) specifies the V
30 coordinate of the point being rotated.
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32 WCRD (an input/output variable of type REAL) specifies the W
33 coordinate of the point being rotated.
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36 The C binding argument descriptions are the same as the FORTRAN
37 argument descriptions.
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40 This routine is used by NGGCOG and NGGSOG to effect the rotations that
41 are used to generate an object of a specified shape at a specified
42 point on the surface of the globe.
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44 NGRITD assumes that the UVW coordinate system is right-handed.
45 Positive values of ANGL give counter-clockwise rotations and negative
46 values of ANGL give clockwise rotations. (When IAXS = 1, ANGL = 90
47 carries the positive V axis into the positive W axis; when IAXS = 2,
48 ANGL = 90 carries the positive W axis into the positive U axis; when
49 IAXS = 3, ANGL = 90 carries the positive U axis into the positive V
50 axis.)
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53 Use the ncargex command to see the following relevant example: cpex10.
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56 To use NGRITD or c_ngritd, load the NCAR Graphics libraries ncarg,
57 ncarg_gks, and ncarg_c, preferably in that order.
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60 None.
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63 Online: nggcog(3NCARG), nggsog(3NCARG).
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66 Copyright (C) 1987-2009
67 University Corporation for Atmospheric Research
68 The use of this Software is governed by a License Agreement.
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72UNIX March 1993 NGRITD(3NCARG)