Ubuntu Manpage: STINIT - Performs initialization tasks required before STREAM may be called to create a

Provided by: libncarg-dev_6.6.2.dfsg.1-2_amd64

NAME

       STINIT - Performs initialization tasks required before STREAM may be called to create a
       streamline field flow plot.  Information about the input data arrays is copied into
       internal common block variables and the coordinate system mappings and boundaries are
       established.

SYNOPSIS

       CALL STINIT (U,LU,V,LV,P,LP,M,N,WRK,LW)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_stinit(float *u, int lu, float *v, int lv,
                     float *p, int lp, int m, int n,
                     float *wrk, int lw)

DESCRIPTION

U (REAL 2-dimensional array, dimensioned LU x n: n >= N, input): By default,
assumed to contain the first dimensional Cartesian components of the vector
field. However, if PLR is non-zero, it is treated as containing the vector
magnitudes.

LU (INTEGER, input): Actual value of the first dimension of array U.

V (REAL 2-dimensional array, dimensioned LV x n: n >= N, input): By default,
assumed to contain the second dimensional Cartesian components of the vector
field. However, if PLR is non-zero, it is treated as containing the vector
angles.

LV (INTEGER, input): Actual value of the first dimension of array V.

P (REAL, input, DUMMY): This argument is currently ignored and may be assigned a
dummy value.

LP (INTEGER, input, DUMMY): The first dimension of array P. Not currently used,
this argument should be assigned the integer value 0.

M (INTEGER, input): Number of contiguous elements along the first dimensional
axis containing data to be processed in each of the arrays, U and V.

N (INTEGER, input): Number of contiguous elements along the second dimensional
axis containing data to be processed in each of the arrays, U and V.

WRK (REAL, array dimensioned n: n >= LW, input/output): Work array used to store
normalized values of the U and V vector components while the streamlines are
calculated. It also holds bit flags indicating whether a grid location is
eligible for starting a streamline or placing a directional arrowhead.

LW (INTEGER, input): Assumed size of the array WRK. Currently it must greater or
equal to 2*M*N.

C-BINDING DESCRIPTION

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions,
       with the following exceptions:

       lu          The second dimension of u in the calling program.

       lv          The second dimension of v in the calling program.

       lp          The second dimension of p in the calling program.

       m           Number of contiguous elements along the second dimension containing data to be
                   processed in each of the arrays, u and v.

       n           Number of contiguous elements along the first dimension containing data to be
                   processed in each of the arrays, u and v.

USAGE

Call STINIT before the first invocation of STREAM, and again anytime you modify the
contents of the input data arrays. You may precede an STINIT call with any number of calls
to the parameter setting routines, STSETR and STSETI. Although it is possible to call
STSETI or STSETR between calls to STINIT and STREAM, changing the setting of many of
Streamline's parameters at this point will result in incorrect behavior. When in doubt,
set parameters before the STINIT call; see the streamlines_params man page for more
information.

Set up the two vector component arrays prior to calling STINIT. To permit multiple
purpose use of the array space, the STINIT argument list includes both the actual size and
an assumed size for the first dimension of each input array. Due to FORTRAN array ordering
conventions, only the assumed size needs to be specified for the second dimension. (Note:
when using the C bindings, mentally exchange all references to first and second dimensions
in this discussion.) The arguments LU and LV contain the actual size of the first
dimensions of U and V, respectively. Since the grid locations for each of the data arrays
are assumed to coincide, a single argument, M, represents the assumed size of the first
dimension for both arrays. Similarly, the argument, N, is the assumed size of the second
dimension. The only requirement for the actual second dimension size is that it be greater
than or equal to N for each array.

The P and LP arguments are intended for future enhancement of the Streamlines utility.
They are not currently used or examined in any way. For maximum assurance of compatibility
with future changes to the code, give the LP argument the INTEGER value 0.

WRK is an array used to store normalized values of the U and V vector components while the
streamlines are calculated. It also holds bit flags indicating whether a grid location is
eligible for starting a streamline or placing a directional arrowhead. Its assumed size is
specified by the argument LW. LW must have a value greater or equal to 2*M*N.

EXAMPLES

       Use the ncargex command to see the following relevant examples: ffex00, ffex01, ffex03,
       ffex04, fstream, stex01, stex02, stex03.

ACCESS

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

MESSAGES

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

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.