The following ``ANSI-C'' code calculates the minimum number of bytes necessary to allocate in a shared memory segment, that will be used for FIT2D program arrays. The number of bytes is dependent on the size of the program arrays to create (xmaxdat and ymaxdat), and on whether or not ``memory arrays'' and ``variance arrays'' are to be created.
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*** * *
*** * f2d_sharedsizec.c *
*** * *
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*/
#define _POSIX_SOURCE 1
#include <stdio.h>
/*+ F2D_SHAREDSIZEC: calculate Shared memory Size */
int f2d_sharedsizec /* Returns number of bytes needed for shared memory */
(int xmaxdat, /* Dimension size in X-direction for data arrays */
int ymaxdat, /* Dimension size in Y-direction for data arrays */
int memory_exist, /* "True" if memory arrays are to be created */
int variances_exist) /* "True", if a data variance arrays are to be created */
/* Description:
* Calculates minimum size for shared memory segment given requirements
* for memory arrays and variance arrays.
* Status:
* Method:
* Bugs:
* Authors:
* A P Hammersley (hammersley@esrf.fr)
* History:
* 19-Nov-2003: V0.1 Original (Hammersley)
* Import: */
/* Status: */
/* Extra "C" Variables: */
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{
/* Local Variables: */
int num_bytes; /* Number of bytes necessary for FIT2D arrays */
/* Basic current data arrays */
num_bytes = xmaxdat * ymaxdat * sizeof(float); /* "DATA" */
num_bytes = num_bytes + xmaxdat * ymaxdat * sizeof(char); /* "MASK" */
num_bytes = num_bytes + xmaxdat * sizeof(float); /* "XAXIS" */
num_bytes = num_bytes + ymaxdat * sizeof(float); /* "YAXIS" */
/* Memory arrays */
if (memory_exist) {
num_bytes = num_bytes + xmaxdat * ymaxdat * sizeof(float); /* "MDATA" */
num_bytes = num_bytes + xmaxdat * sizeof(float); /* "MXAXIS" */
num_bytes = num_bytes + ymaxdat * sizeof(float); /* "MYAXIS" */
}
/* Variance arrays */
if (variances_exist) {
num_bytes = num_bytes + xmaxdat * ymaxdat * sizeof(float); /* "VARIANCES" */
if (memory_exist) { /* "MVARIANCES" */
num_bytes = num_bytes + xmaxdat * ymaxdat * sizeof(float);
}
}
/* Return number of bytes to allocate */
return num_bytes;
/* End of Function f2d_sharedsizec */
}