Writing character data through SDwritedata()

Hdf-forum archives
1

Folks
I am trying to write a simple character array through SDwritedata but
somehow my output SDS field ends up being of 32 bit floating bit type and
the values are all big floating point values. What am I doing wrong? See
some portions of my code below:

char * ref_name = NULL:
int32 ndata;
int i;

ndata = 7;
ioparam->out_sds.data_type = DFNT_CHAR;
ioparam->out_sds.data_size = DFKNTsize(ioparam->out_sds.data_type);

for (i = 0; i < ndata; i++) /* BIG Assumption that ref data will be always
1D */
      {
        ref_name = (void *) calloc (size, sizeof(char));
        status = get_name (foo, ref_name, size); /* Here the ref_name is
set */
        start[0] = i;
        edge[0] = 1;
        printf("Dataset: %s is %s\n",ioparam->in_sds.name,ref_name); /*
Here the names are printed correctly */
        if (SDwritedata(ioparam->out_sds.sds_id, start, NULL, edge,
(VOIDP)ref_name) == FAIL) {
          fprintf(stderr, "Error writing ref data from SDS %s\n", ioparam->
out_sds.name);
          return -1;
        }
        if (ref_name != NULL) free(ref_name);
      }

So the names are all printed correctly when I print them on the screen but
when I check the output file the fields are all float32.

Am I missing something here?
Thanks

2

Hi,

Are you creating the dataset with a float datatype?

Attached is an HDF4 program that creates a character dataset.
It creates the dataset as follows:

    sds_id = SDcreate(sd_id, "data1", DFNT_CHAR, rank, dims);

-Barbara

sdtxt.c (1.3 KB)

···

====================
Barbara Jones
The HDF Helpdesk

The HDF Group
help@hdfgroup.org

Folks
I am trying to write a simple character array through SDwritedata but
somehow my output SDS field ends up being of 32 bit floating bit type and
the values are all big floating point values. What am I doing wrong? See
some portions of my code below:

char * ref_name = NULL:
int32 ndata;
int i;

ndata = 7;
ioparam->out_sds.data_type = DFNT_CHAR;
ioparam->out_sds.data_size = DFKNTsize(ioparam->out_sds.data_type);

for (i = 0; i < ndata; i++) /* BIG Assumption that ref data will be always
1D */
     {
       ref_name = (void *) calloc (size, sizeof(char));
       status = get_name (foo, ref_name, size); /* Here the ref_name is
set */
       start[0] = i;
       edge[0] = 1;
       printf("Dataset: %s is %s\n",ioparam->in_sds.name,ref_name); /*
Here the names are printed correctly */
       if (SDwritedata(ioparam->out_sds.sds_id, start, NULL, edge,
(VOIDP)ref_name) == FAIL) {
         fprintf(stderr, "Error writing ref data from SDS %s\n", ioparam->
out_sds.name);
         return -1;
       }
       if (ref_name != NULL) free(ref_name);
     }

So the names are all printed correctly when I print them on the screen but
when I check the output file the fields are all float32.

Am I missing something here?
Thanks

--
Barbara L. Jones
bljones@hdfgroup.org

3

Appreciated your help and thanks for that reply. I found that mistake soon
after I mailed.
BTW I have not looked at your other suggestion for reading HDf5 data row by
row. I will look at your program and see what am I doing wrong.
Thanks and regards

···

On Wed, Oct 17, 2012 at 11:43 AM, Barbara Jones <bljones@hdfgroup.org>wrote:

Hi,

Are you creating the dataset with a float datatype?

Attached is an HDF4 program that creates a character dataset.
It creates the dataset as follows:

   sds_id = SDcreate(sd_id, "data1", DFNT_CHAR, rank, dims);

-Barbara

====================
Barbara Jones
The HDF Helpdesk

The HDF Group
help@hdfgroup.org

Folks

I am trying to write a simple character array through SDwritedata but
somehow my output SDS field ends up being of 32 bit floating bit type and
the values are all big floating point values. What am I doing wrong? See
some portions of my code below:

char * ref_name = NULL:
int32 ndata;
int i;

ndata = 7;
ioparam->out_sds.data_type = DFNT_CHAR;
ioparam->out_sds.data_size = DFKNTsize(ioparam->out_sds.**data_type);

for (i = 0; i < ndata; i++) /* BIG Assumption that ref data will be always
1D */
     {
       ref_name = (void *) calloc (size, sizeof(char));
       status = get_name (foo, ref_name, size); /* Here the ref_name is
set */
       start[0] = i;
       edge[0] = 1;
       printf("Dataset: %s is %s\n",ioparam->in_sds.name,**ref_name); /*
Here the names are printed correctly */
       if (SDwritedata(ioparam->out_sds.**sds_id, start, NULL, edge,
(VOIDP)ref_name) == FAIL) {
         fprintf(stderr, "Error writing ref data from SDS %s\n", ioparam->
out_sds.name);
         return -1;
       }
       if (ref_name != NULL) free(ref_name);
     }

So the names are all printed correctly when I print them on the screen but
when I check the output file the fields are all float32.

Am I missing something here?
Thanks

--
Barbara L. Jones
bljones@hdfgroup.org
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