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http://www.hackerschool.org/HS_Boards/zboard.php?AllArticle=true&no=6574 [복사]
#include <stdio.h>
#include <stdlib.h>
typedef int boolean;
#define true 1
#define false 0
#define M 5
#define N 30
#define winSize 250
#define HP_CONSTANT ((float) 1 / (float) M)
void detect(float* ecg, int* result, int len);
int main(int argc, char** argv){
float new_pt;
float ecg[1000000] = { 0 };
int result[1000000] = { 0 };
int i=0, j;
// read in ECG data
FILE *fid = NULL;
if (argc > 1){
fid = fopen(argv[1], "r");
}
else{
fid = fopen("100.text", "r");
}
while (EOF != fscanf(fid, "%f\n", &new_pt)){
ecg[i++] = new_pt;
// printf("%f\n", new_pt);
}
fclose(fid);
// perform realtime QRS detection
detect(ecg, result, i);
// save detection results
fid = fopen("101.text", "w");
for (j = 0; j < i; j++){
fprintf(fid, "%d\n", result[j]);
}
fclose(fid);
return 0;
}
void detect(float* ecg, int* result, int len) {
// circular buffer for input ecg signal
// we need to keep a history of M + 1 samples for HP filter
float ecg_buff[M + 1] = { 0 };
int ecg_buff_WR_idx = 0;
int ecg_buff_RD_idx = 0;
// circular buffer for input ecg signal
// we need to keep a history of N+1 samples for LP filter
float hp_buff[N + 1] = { 0 };
int hp_buff_WR_idx = 0;
int hp_buff_RD_idx = 0;
// LP filter outputs a single point for every input point
// This goes straight to adaptive filtering for eval
float next_eval_pt = 0;
// running sums for HP and LP filters, values shifted in FILO
float hp_sum = 0;
float lp_sum = 0;
// parameters for adaptive thresholding
double treshold = 0;
boolean triggered = false;
int trig_time = 0;
float win_max = 0;
int win_idx = 0;
int i = 0;
for (i = 0; i < len; i++){
ecg_buff[ecg_buff_WR_idx++] = ecg[i];
ecg_buff_WR_idx %= (M + 1);
//printf("i - %d\n", i);
/* High pass filtering */
if (i < M){
// first fill buffer with enough points for HP filter
hp_sum += ecg_buff[ecg_buff_RD_idx];
hp_buff[hp_buff_WR_idx] = 0;
//printf("hp_buff[hp_buff_WR_idx] - %f\n", hp_buff[hp_buff_WR_idx]);
}
else{
hp_sum += ecg_buff[ecg_buff_RD_idx];
int tmp = ecg_buff_RD_idx - M;
if (tmp < 0) tmp += M + 1;
hp_sum -= ecg_buff[tmp];
float y1 = 0;
float y2 = 0;
tmp = (ecg_buff_RD_idx - ((M + 1) / 2));
if (tmp < 0) tmp += M + 1;
y2 = ecg_buff[tmp];
y1 = HP_CONSTANT * hp_sum;
hp_buff[hp_buff_WR_idx] = y2 - y1;
//printf("hp_buff[hp_buff_WR_idx] - %f\n", hp_buff[hp_buff_WR_idx]);
}
// done reading ECG buffer, increment position
ecg_buff_RD_idx++;
ecg_buff_RD_idx %= (M + 1);
// done writing to HP buffer, increment position
hp_buff_WR_idx++;
hp_buff_WR_idx %= (N + 1);
/* Low pass filtering */
// shift in new sample from high pass filter
lp_sum += hp_buff[hp_buff_RD_idx] * hp_buff[hp_buff_RD_idx];
if (i < N){
// first fill buffer with enough points for LP filter
next_eval_pt = 0;
}
else{
// shift out oldest data point
int tmp = hp_buff_RD_idx - N;
if (tmp < 0) tmp += N + 1;
lp_sum -= hp_buff[tmp] * hp_buff[tmp];
next_eval_pt = lp_sum;
}
// done reading HP buffer, increment position
hp_buff_RD_idx++;
hp_buff_RD_idx %= (N + 1);
/* Adapative thresholding beat detection */
// set initial threshold
if (i < winSize) {
if (next_eval_pt > treshold) {
treshold = next_eval_pt;
}
}
// check if detection hold off period has passed
if (triggered){
trig_time++;
if (trig_time >= 100){
triggered = false;
trig_time = 0;
}
}
// find if we have a new max
if (next_eval_pt > win_max) win_max = next_eval_pt;
// find if we are above adaptive threshold
if (next_eval_pt > treshold && !triggered) {
result[i] = 1;
triggered = true;
}
else {
result[i] = 0;
}
// adjust adaptive threshold using max of signal found
// in previous window
if (win_idx++ >= winSize){
// weighting factor for determining the contribution of
// the current peak value to the threshold adjustment
double gamma = 0.175;
// forgetting factor -
// rate at which we forget old observations
double alpha = 0.01 + (((float)rand() / (float)RAND_MAX) * ((0.1 - 0.01)));
treshold = alpha * gamma * win_max + (1 - alpha) * treshold;
// reset current window ind
win_idx = 0;
win_max = -10000000;
}
}
}
위 에 코딩이고요 ㅠㅠ
0x009120C7에(QRS.exe의) 첫째 예외가 있습니다. 0xC00000FD: Stack overflow(매개 변수: 0x00000000, 0x00552000).
0x009120C7에(QRS.exe의) 처리되지 않은 예외가 있습니다. 0xC00000FD: Stack overflow(매개 변수: 0x00000000, 0x00552000).
이렇게 뜨네요 전자공학과 인데 코딩을 하련 힘드네요 ㅠㅠ |
Hit : 6618 Date : 2017/03/26 02:23
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