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read_eep_cnt.c
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Fri, Apr 18, 22:16

read_eep_cnt.c
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/********************************************************************************
* *
* this file is part of: *
* libeep, the project for reading and writing avr/cnt eeg and related files *
* *
********************************************************************************
* *
* LICENSE:Copyright (c) 2003-2009, *
* Advanced Neuro Technology (ANT) B.V., Enschede, The Netherlands *
* Max-Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany *
* *
********************************************************************************
* *
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library is distributed WITHOUT ANY WARRANTY; even the implied warranty *
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
* *
*******************************************************************************/
#include <math.h>
#include "mex.h" /* Matlab specific */
#include "matrix.h" /* Matlab specific */
#include <eep/eepmisc.h> /* MPI-ANT specific */
#include <cnt/cnt.h> /* MPI-ANT specific */
#define NAME "read_eep_cnt"
void
mexFunction (int nlhs, mxArray * plhs[], int nrhs, const mxArray * prhs[]) {
/* these variables are MPI-ANT specific for reading the data */
char filename[256];
int chan, sample, sb, se, length, chanc, samplec;
float period;
int status;
FILE *fp;
sraw_t *buf;
eeg_t *hdr;
/* these variables are Matlab specific for interfacing */
double *ptr;
const int dims[] = {1, 1};
mxArray *label;
mxArray *rate;
mxArray *npnt;
mxArray *nchan;
mxArray *nsample;
mxArray *time;
mxArray *data;
mxArray *triggers;
const int nfields = 8;
const char *field_names[] = {
"label", /* label */
"rate", /* 1/(period) */
"npnt", /* nsample of this segment */
"nchan", /* chanc */
"nsample", /* nsample of the whole data */
"time", /* */
"triggers", /* */
"data"
}; /* data */
trg_t * trigger_struct;
const int trigger_field_count = 4;
const char * trigger_field_names[] = { "time", "offset", "code", "type"};
int trigger_array_index;
int trigger_index;
int trigger_count;
char * trigger_label;
unsigned long long trigger_offset;
if (nrhs!=3)
mexErrMsgTxt ("Invalid number of input arguments");
mxGetString(prhs[0], filename, 256);
sb = (int)(mxGetScalar(prhs[1]) + 0.5) - 1;
se = (int)(mxGetScalar(prhs[2]) + 0.5) - 1;
length = se-sb+1;
/* open the data file */
if ((fp = eepio_fopen(filename, "rb"))==NULL)
mexErrMsgTxt ("Could not open file");
/* read header information */
hdr = eep_init_from_file(filename, fp, &status);
if ((hdr == NULL) || (status!=CNTERR_NONE))
mexErrMsgTxt ("Error reading header from file");
chanc = eep_get_chanc(hdr);
period = eep_get_period(hdr);
samplec = eep_get_samplec(hdr);
if (sb<0)
mexErrMsgTxt ("Begin sample should be 1 or larger");
if (se<sb)
mexErrMsgTxt ("End sample should be similar to, or larger than the begin sample");
if (chanc<1)
mexErrMsgTxt ("Invalid number of channels in the data");
if (se>samplec)
mexErrMsgTxt ("End sample should be less than the number of samples in the data");
/* rate = mxCreateDoubleMatrix(1,1,mxREAL); *mxGetPr(rate ) = (double)1/period; */
rate = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(rate ) = (double)eep_get_rate(hdr);
npnt = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(npnt ) = (double)length;
nchan = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(nchan ) = (double)chanc;
nsample = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(nsample ) = (double)samplec;
data = mxCreateDoubleMatrix(chanc,length,mxREAL);
time = mxCreateDoubleMatrix(1,length,mxREAL);
label = mxCreateCellMatrix(chanc,1);
ptr = mxGetPr(time);
for (sample=0; sample<length; sample++)
ptr[sample] = (double)1000*(sb+sample)*period;
for (chan=0; chan<chanc; chan++)
mxSetCell(label,chan,mxCreateString(eep_get_chan_label(hdr, chan)));
/* allocate memory for the data and read it from file */
buf = (sraw_t *)malloc(CNTBUF_SIZE(hdr, chanc));
ptr = mxGetPr(data);
eep_seek(hdr, DATATYPE_EEG, sb, 0);
for (sample=0; sample<length; sample++)
if (eep_read_sraw(hdr, DATATYPE_EEG, buf, 1) != CNTERR_NONE)
mexErrMsgTxt ("Error reading raw data from file");
else
for (chan=0; chan<chanc; chan++)
ptr[sample*chanc+chan] = eep_get_chan_scale(hdr, chan) * buf[chan];
/* create the struct array with dimensions 1x1 */
plhs[0] = mxCreateStructArray(2, dims, nfields, field_names);
/* trigger stuff */
trigger_struct = eep_get_trg(hdr);
if(trigger_struct != NULL) {
// pass one, count triggers
trigger_count = 0;
for(trigger_index=0;trigger_index<trg_get_c(trigger_struct);trigger_index++) {
trigger_label = trg_get(trigger_struct, trigger_index, & trigger_offset);
if( (trigger_offset >= sb) && (trigger_offset < se) ) {
trigger_count++;
}
}
// pass two, fill triggers
triggers = mxCreateStructMatrix(1, trigger_count, trigger_field_count, trigger_field_names);
trigger_array_index = 0;
for(trigger_index=0;trigger_index<trg_get_c(trigger_struct);trigger_index++) {
trigger_label = trg_get(trigger_struct, trigger_index, & trigger_offset);
if(trigger_offset >= sb && trigger_offset < se) {
mxArray * time;
mxArray * offset;
mxArray * code;
mxArray * type;
time = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(time) = (double) trigger_offset * period;
offset = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(offset) = (double) trigger_offset;
code = mxCreateString(trigger_label);
type = mxCreateDoubleMatrix(1,1,mxREAL);
*mxGetPr(type) = (double) atof(trigger_label);
/* fill the struct array with the variables */
mxSetField(triggers, trigger_array_index, "time", time );
mxSetField(triggers, trigger_array_index, "offset", offset );
mxSetField(triggers, trigger_array_index, "code", code );
mxSetField(triggers, trigger_array_index, "type", type );
trigger_array_index++;
}
}
}
/* fill the struct array with the variables */
mxSetField(plhs[0], 0, "rate", rate );
mxSetField(plhs[0], 0, "npnt", npnt );
mxSetField(plhs[0], 0, "nchan", nchan );
mxSetField(plhs[0], 0, "nsample", nsample );
mxSetField(plhs[0], 0, "data", data );
mxSetField(plhs[0], 0, "time", time );
mxSetField(plhs[0], 0, "label", label );
mxSetField(plhs[0], 0, "triggers", triggers );
/* close the file */
eep_free(hdr);
eepio_fclose(fp);
free(buf);
return;
}

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