/* updated to FP support 11/99 Markus Neteler */

/*****************/

/** gaussurf()        **/

/*****************/

#include <unistd.h>
#include <math.h>
#include <grass/gis.h>
#include <grass/raster.h>
#include <grass/gmath.h>

int gaussurf(char *out, /* Name of raster maps to be opened.    */
             double mean, double sigma /* Distribution parameters. */
)
{
    int nrows, ncols; /* Number of cell rows and columns      */

    DCELL *row_out; /* Buffer just large enough to hold one */

    /* row of the raster map layer.         */

    int fd_out; /* File descriptor - used to identify   */

    /* open raster maps.                    */
    struct History history; /* cmd line history metadata            */

    int row_count, col_count;

    /****** OPEN CELL FILES AND GET CELL DETAILS ******/

    fd_out = Rast_open_new(out, DCELL_TYPE);

    nrows = Rast_window_rows();
    ncols = Rast_window_cols();

    row_out = Rast_allocate_d_buf();

    /****** PASS THROUGH EACH CELL ASSIGNING RANDOM VALUE ******/

    for (row_count = 0; row_count < nrows; row_count++) {
        G_percent(row_count, nrows, 5);
        for (col_count = 0; col_count < ncols; col_count++)
            *(row_out + col_count) = (DCELL)(G_math_rand_gauss(sigma) + mean);

        /* Write contents row by row */
        Rast_put_d_row(fd_out, (DCELL *)row_out);
    }
    G_percent(1, 1, 1);

    /****** CLOSE THE CELL FILE ******/

    Rast_close(fd_out);
    Rast_short_history(out, "raster", &history);
    Rast_command_history(&history);
    Rast_write_history(out, &history);

    return 0;
}
