My first post to this list, so go easy.
I've been playing with the r.walk code for my own purposes. I've been
trying to add functionality for a second output file. Basically I
copied everything done to the original output file, but with different
file names. The odd thing is, that I get a seg fault on
segment_put(&out_seg2, &fbuff[i], row, i); when above it worked
fine for the original &out_seg. The relevent bits of code are below
(though tell me if I should post the whole thing):
void *dtm_cell, *cost_cell, *cum_cell, *dir_cell, *cell2 = NULL;
//cn: added dir_cell
SEGMENT dtm_in_seg, cost_in_seg, out_seg, out_seg2; //cn: added
out_seg2 for move dir
char *cum_cost_mapset, *move_dir_mapset; //cn: added move_dir_mapset
char *dtm_in_file, *cost_in_file, *out_file, *dir_out_file; //cn:
added dir_out_file
double *dtm_value, *cost_value, *value_start_pt, *dir_value; //cn:
and dir_value
double cur_dir, old_cur_dir; //cn: added cur_dir and old_cur_dir
int cost_fd, cum_fd, dtm_fd, dir_fd; //cn:added dir_fd
int dtm_in_fd, cost_in_fd, out_fd, dir_out_fd; //cn: added dir_out_fd
struct Option *opt9, *opt10, *opt11, *opt12, *opt13, *opt14,
*opt15; //cn: added *opt15
...
/*CN: added the opt for outputing the raster of movement directions*/
opt15 = G_define_option();
opt15->key = "outdir";
opt15->type = TYPE_STRING;
opt15->required = YES;
opt15->gisprompt = "new,cell,raster";
opt15->description = _("Name of output raster map to contain
movement directions");
...
strcpy(cum_cost_layer, opt1->answer);
current_mapset = G_mapset();
/* Search for output layer (cum_cost_layer) in all mapsets */
search_mapset = "";
cum_cost_mapset = G_find_cell2(cum_cost_layer, search_mapset);
/*CN: Copy the specified filename to a new file*/
strcpy(move_dir_layer, opt15->answer);
/*CN: Search for output layer (move_dir_layer) in mapsets*/
search_mapset = "";
move_dir_mapset = G_find_cell2(move_dir_layer, search_mapset);
...
if (G_legal_filename(cum_cost_layer) < 0)
G_fatal_error(_("<%s> is an illegal file name"), cum_cost_layer);
/*CN: check if layer name is legal*/
if (G_legal_filename(move_dir_layer) < 0)
G_fatal_error(_("<%s> is an illegal file name"), move_dir_layer);
...
out_fd = creat(out_file, 0600);
segment_format(out_fd, nrows, ncols, srows, scols, sizeof(double));
close(out_fd);
/*cn: create a seg file for dir output*/
dir_out_fd = creat(dir_out_file, 0600);
segment_format(dir_out_fd, nrows, ncols, srows, scols, sizeof(double));
close(dir_out_fd);
...
out_fd = open(out_file, 2);
segment_init(&out_seg, out_fd, segments_in_memory);
/*cn: and the dir output file*/
dir_out_fd = open(dir_out_file, 2);
segment_init(&out_seg2, dir_out_fd, segments_in_memory);
...
/* Initialize output map with NULL VALUES */
/* Initialize segmented output file */
G_message(_("Initializing output "));
{
double *fbuff;
int i;
fbuff = (double *)G_malloc((unsigned int)(ncols * sizeof(double)));
if (fbuff == NULL)
G_fatal_error(_("Unable to allocate memory for segment fbuff == NULL"));
G_set_d_null_value(fbuff, ncols);
for (row = 0; row < nrows; row++) {
{
G_percent(row, nrows, 2);
}
for (i = 0; i < ncols; i++) {
segment_put(&out_seg, &fbuff[i], row, i);
}
}
segment_flush(&out_seg);
G_percent(row, nrows, 2);
G_free(fbuff);
}
/*cn:init segmented dir output file */
G_message(_("Initializing directional output "));
{
double *fbuff;
G_message(_("*fbuff"));
int i;
fbuff = (double *)G_malloc((unsigned int)(ncols * sizeof(double)));
G_message(_("fbuff"));
if (fbuff == NULL)
G_fatal_error(_("Unable to allocate memory for segment fbuff == NULL"));
G_set_d_null_value(fbuff, ncols);
G_message(_("set_d_null"));
for (row = 0; row < nrows; row++) {
{
G_percent(row, nrows, 2);
}
for (i = 0; i < ncols; i++) {
G_message(_("almost seg_put <%d>"), &fbuff[i]);
segment_put(&out_seg2, &fbuff[i], row, i);
G_message(_("done seg_put"));
}
}
G_message(_("almost seg_flush"));
segment_flush(&out_seg2);
G_message(_("done seg_flush"));
G_percent(row, nrows, 2);
G_free(fbuff);
G_message(_("G_free"));
}
It compiles fine but when I run it, I get a segmentation fault at
segment_put(&out_seg2,....
Thanks, I hope someone can help.
-CN