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Dependencies:   mbed

algorithm/algorithm.cpp@1:bf043e9adc7a, 2019-09-30 (annotated)

Committer:
tenvinc
Date:
Mon Sep 30 12:56:04 2019 +0000
Revision:
1:bf043e9adc7a
Parent:
0:864a1ca8699e 
Added MAX30001 library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tenvinc 0:864a1ca8699e 1 /** \file algorithm.cpp ******************************************************
tenvinc 0:864a1ca8699e 2 *
tenvinc 0:864a1ca8699e 3 * Project: MAXREFDES117#
tenvinc 0:864a1ca8699e 4 * Filename: algorithm.cpp
tenvinc 0:864a1ca8699e 5 * Description: This module calculates the heart rate/SpO2 level
tenvinc 0:864a1ca8699e 6 *
tenvinc 0:864a1ca8699e 7 *
tenvinc 0:864a1ca8699e 8 * --------------------------------------------------------------------
tenvinc 0:864a1ca8699e 9 *
tenvinc 0:864a1ca8699e 10 * This code follows the following naming conventions:
tenvinc 0:864a1ca8699e 11 *
tenvinc 0:864a1ca8699e 12 * char ch_pmod_value
tenvinc 0:864a1ca8699e 13 * char (array) s_pmod_s_string[16]
tenvinc 0:864a1ca8699e 14 * float f_pmod_value
tenvinc 0:864a1ca8699e 15 * int32_t n_pmod_value
tenvinc 0:864a1ca8699e 16 * int32_t (array) an_pmod_value[16]
tenvinc 0:864a1ca8699e 17 * int16_t w_pmod_value
tenvinc 0:864a1ca8699e 18 * int16_t (array) aw_pmod_value[16]
tenvinc 0:864a1ca8699e 19 * uint16_t uw_pmod_value
tenvinc 0:864a1ca8699e 20 * uint16_t (array) auw_pmod_value[16]
tenvinc 0:864a1ca8699e 21 * uint8_t uch_pmod_value
tenvinc 0:864a1ca8699e 22 * uint8_t (array) auch_pmod_buffer[16]
tenvinc 0:864a1ca8699e 23 * uint32_t un_pmod_value
tenvinc 0:864a1ca8699e 24 * int32_t * pn_pmod_value
tenvinc 0:864a1ca8699e 25 *
tenvinc 0:864a1ca8699e 26 * ------------------------------------------------------------------------- */
tenvinc 0:864a1ca8699e 27 /*******************************************************************************
tenvinc 0:864a1ca8699e 28 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
tenvinc 0:864a1ca8699e 29 *
tenvinc 0:864a1ca8699e 30 * Permission is hereby granted, free of charge, to any person obtaining a
tenvinc 0:864a1ca8699e 31 * copy of this software and associated documentation files (the "Software"),
tenvinc 0:864a1ca8699e 32 * to deal in the Software without restriction, including without limitation
tenvinc 0:864a1ca8699e 33 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
tenvinc 0:864a1ca8699e 34 * and/or sell copies of the Software, and to permit persons to whom the
tenvinc 0:864a1ca8699e 35 * Software is furnished to do so, subject to the following conditions:
tenvinc 0:864a1ca8699e 36 *
tenvinc 0:864a1ca8699e 37 * The above copyright notice and this permission notice shall be included
tenvinc 0:864a1ca8699e 38 * in all copies or substantial portions of the Software.
tenvinc 0:864a1ca8699e 39 *
tenvinc 0:864a1ca8699e 40 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
tenvinc 0:864a1ca8699e 41 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
tenvinc 0:864a1ca8699e 42 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
tenvinc 0:864a1ca8699e 43 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
tenvinc 0:864a1ca8699e 44 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
tenvinc 0:864a1ca8699e 45 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
tenvinc 0:864a1ca8699e 46 * OTHER DEALINGS IN THE SOFTWARE.
tenvinc 0:864a1ca8699e 47 *
tenvinc 0:864a1ca8699e 48 * Except as contained in this notice, the name of Maxim Integrated
tenvinc 0:864a1ca8699e 49 * Products, Inc. shall not be used except as stated in the Maxim Integrated
tenvinc 0:864a1ca8699e 50 * Products, Inc. Branding Policy.
tenvinc 0:864a1ca8699e 51 *
tenvinc 0:864a1ca8699e 52 * The mere transfer of this software does not imply any licenses
tenvinc 0:864a1ca8699e 53 * of trade secrets, proprietary technology, copyrights, patents,
tenvinc 0:864a1ca8699e 54 * trademarks, maskwork rights, or any other form of intellectual
tenvinc 0:864a1ca8699e 55 * property whatsoever. Maxim Integrated Products, Inc. retains all
tenvinc 0:864a1ca8699e 56 * ownership rights.
tenvinc 0:864a1ca8699e 57 *******************************************************************************
tenvinc 0:864a1ca8699e 58 */
tenvinc 0:864a1ca8699e 59 #include "algorithm.h"
tenvinc 0:864a1ca8699e 60 #include "mbed.h"
tenvinc 0:864a1ca8699e 61
tenvinc 0:864a1ca8699e 62 void maxim_heart_rate_and_oxygen_saturation(uint32_t *pun_ir_buffer, int32_t n_ir_buffer_length, uint32_t *pun_red_buffer, int32_t *pn_spo2, int8_t *pch_spo2_valid,
tenvinc 0:864a1ca8699e 63 int32_t *pn_heart_rate, int8_t *pch_hr_valid)
tenvinc 0:864a1ca8699e 64 /**
tenvinc 0:864a1ca8699e 65 * \brief Calculate the heart rate and SpO2 level
tenvinc 0:864a1ca8699e 66 * \par Details
tenvinc 0:864a1ca8699e 67 * By detecting peaks of PPG cycle and corresponding AC/DC of red/infra-red signal, the ratio for the SPO2 is computed.
tenvinc 0:864a1ca8699e 68 * Since this algorithm is aiming for Arm M0/M3. formaula for SPO2 did not achieve the accuracy due to register overflow.
tenvinc 0:864a1ca8699e 69 * Thus, accurate SPO2 is precalculated and save longo uch_spo2_table[] per each ratio.
tenvinc 0:864a1ca8699e 70 *
tenvinc 0:864a1ca8699e 71 * \param[in] *pun_ir_buffer - IR sensor data buffer
tenvinc 0:864a1ca8699e 72 * \param[in] n_ir_buffer_length - IR sensor data buffer length
tenvinc 0:864a1ca8699e 73 * \param[in] *pun_red_buffer - Red sensor data buffer
tenvinc 0:864a1ca8699e 74 * \param[out] *pn_spo2 - Calculated SpO2 value
tenvinc 0:864a1ca8699e 75 * \param[out] *pch_spo2_valid - 1 if the calculated SpO2 value is valid
tenvinc 0:864a1ca8699e 76 * \param[out] *pn_heart_rate - Calculated heart rate value
tenvinc 0:864a1ca8699e 77 * \param[out] *pch_hr_valid - 1 if the calculated heart rate value is valid
tenvinc 0:864a1ca8699e 78 *
tenvinc 0:864a1ca8699e 79 * \retval None
tenvinc 0:864a1ca8699e 80 */
tenvinc 0:864a1ca8699e 81 {
tenvinc 0:864a1ca8699e 82 uint32_t un_ir_mean ,un_only_once ;
tenvinc 0:864a1ca8699e 83 int32_t k ,n_i_ratio_count;
tenvinc 0:864a1ca8699e 84 int32_t i,s ,m, n_exact_ir_valley_locs_count ,n_middle_idx;
tenvinc 0:864a1ca8699e 85 int32_t n_th1, n_npks,n_c_min;
tenvinc 0:864a1ca8699e 86 int32_t an_ir_valley_locs[15] ;
tenvinc 0:864a1ca8699e 87 int32_t an_exact_ir_valley_locs[15] ;
tenvinc 0:864a1ca8699e 88 int32_t an_dx_peak_locs[15] ;
tenvinc 0:864a1ca8699e 89 int32_t n_peak_interval_sum;
tenvinc 0:864a1ca8699e 90
tenvinc 0:864a1ca8699e 91 int32_t n_y_ac, n_x_ac;
tenvinc 0:864a1ca8699e 92 int32_t n_spo2_calc;
tenvinc 0:864a1ca8699e 93 int32_t n_y_dc_max, n_x_dc_max;
tenvinc 0:864a1ca8699e 94 int32_t n_y_dc_max_idx, n_x_dc_max_idx;
tenvinc 0:864a1ca8699e 95 int32_t an_ratio[5],n_ratio_average;
tenvinc 0:864a1ca8699e 96 int32_t n_nume, n_denom ;
tenvinc 0:864a1ca8699e 97 // remove DC of ir signal
tenvinc 0:864a1ca8699e 98 un_ir_mean =0;
tenvinc 0:864a1ca8699e 99 for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ;
tenvinc 0:864a1ca8699e 100 un_ir_mean =un_ir_mean/n_ir_buffer_length ;
tenvinc 0:864a1ca8699e 101 for (k=0 ; k<n_ir_buffer_length ; k++ ) an_x[k] = pun_ir_buffer[k] - un_ir_mean ;
tenvinc 0:864a1ca8699e 102
tenvinc 0:864a1ca8699e 103 // 4 pt Moving Average
tenvinc 0:864a1ca8699e 104 for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
tenvinc 0:864a1ca8699e 105 n_denom= ( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3]);
tenvinc 0:864a1ca8699e 106 an_x[k]= n_denom/(int32_t)4;
tenvinc 0:864a1ca8699e 107 }
tenvinc 0:864a1ca8699e 108
tenvinc 0:864a1ca8699e 109 // get difference of smoothed IR signal
tenvinc 0:864a1ca8699e 110
tenvinc 0:864a1ca8699e 111 for( k=0; k<BUFFER_SIZE-MA4_SIZE-1; k++)
tenvinc 0:864a1ca8699e 112 an_dx[k]= (an_x[k+1]- an_x[k]);
tenvinc 0:864a1ca8699e 113
tenvinc 0:864a1ca8699e 114 // 2-pt Moving Average to an_dx
tenvinc 0:864a1ca8699e 115 for(k=0; k< BUFFER_SIZE-MA4_SIZE-2; k++){
tenvinc 0:864a1ca8699e 116 an_dx[k] = ( an_dx[k]+an_dx[k+1])/2 ;
tenvinc 0:864a1ca8699e 117 }
tenvinc 0:864a1ca8699e 118
tenvinc 0:864a1ca8699e 119 // hamming window
tenvinc 0:864a1ca8699e 120 // flip wave form so that we can detect valley with peak detector
tenvinc 0:864a1ca8699e 121 for ( i=0 ; i<BUFFER_SIZE-HAMMING_SIZE-MA4_SIZE-2 ;i++){
tenvinc 0:864a1ca8699e 122 s= 0;
tenvinc 0:864a1ca8699e 123 for( k=i; k<i+ HAMMING_SIZE ;k++){
tenvinc 0:864a1ca8699e 124 s -= an_dx[k] *auw_hamm[k-i] ;
tenvinc 0:864a1ca8699e 125 }
tenvinc 0:864a1ca8699e 126 an_dx[i]= s/ (int32_t)1146; // divide by sum of auw_hamm
tenvinc 0:864a1ca8699e 127 }
tenvinc 0:864a1ca8699e 128
tenvinc 0:864a1ca8699e 129
tenvinc 0:864a1ca8699e 130 n_th1=0; // threshold calculation
tenvinc 0:864a1ca8699e 131 for ( k=0 ; k<BUFFER_SIZE-HAMMING_SIZE ;k++){
tenvinc 0:864a1ca8699e 132 n_th1 += ((an_dx[k]>0)? an_dx[k] : ((int32_t)0-an_dx[k])) ;
tenvinc 0:864a1ca8699e 133 }
tenvinc 0:864a1ca8699e 134 n_th1= n_th1/ ( BUFFER_SIZE-HAMMING_SIZE);
tenvinc 0:864a1ca8699e 135 // peak location is acutally index for sharpest location of raw signal since we flipped the signal
tenvinc 0:864a1ca8699e 136 maxim_find_peaks( an_dx_peak_locs, &n_npks, an_dx, BUFFER_SIZE-HAMMING_SIZE, n_th1, 8, 5 );//peak_height, peak_distance, max_num_peaks
tenvinc 0:864a1ca8699e 137
tenvinc 0:864a1ca8699e 138 n_peak_interval_sum =0;
tenvinc 0:864a1ca8699e 139 if (n_npks>=2){
tenvinc 0:864a1ca8699e 140 for (k=1; k<n_npks; k++)
tenvinc 0:864a1ca8699e 141 n_peak_interval_sum += (an_dx_peak_locs[k]-an_dx_peak_locs[k -1]);
tenvinc 0:864a1ca8699e 142 n_peak_interval_sum=n_peak_interval_sum/(n_npks-1);
tenvinc 0:864a1ca8699e 143 *pn_heart_rate=(int32_t)(6000/n_peak_interval_sum);// beats per minutes
tenvinc 0:864a1ca8699e 144 *pch_hr_valid = 1;
tenvinc 0:864a1ca8699e 145 }
tenvinc 0:864a1ca8699e 146 else {
tenvinc 0:864a1ca8699e 147 *pn_heart_rate = -999;
tenvinc 0:864a1ca8699e 148 *pch_hr_valid = 0;
tenvinc 0:864a1ca8699e 149 }
tenvinc 0:864a1ca8699e 150
tenvinc 0:864a1ca8699e 151 for ( k=0 ; k<n_npks ;k++)
tenvinc 0:864a1ca8699e 152 an_ir_valley_locs[k]=an_dx_peak_locs[k]+HAMMING_SIZE/2;
tenvinc 0:864a1ca8699e 153
tenvinc 0:864a1ca8699e 154
tenvinc 0:864a1ca8699e 155 // raw value : RED(=y) and IR(=X)
tenvinc 0:864a1ca8699e 156 // we need to assess DC and AC value of ir and red PPG.
tenvinc 0:864a1ca8699e 157 for (k=0 ; k<n_ir_buffer_length ; k++ ) {
tenvinc 0:864a1ca8699e 158 an_x[k] = pun_ir_buffer[k] ;
tenvinc 0:864a1ca8699e 159 an_y[k] = pun_red_buffer[k] ;
tenvinc 0:864a1ca8699e 160 }
tenvinc 0:864a1ca8699e 161
tenvinc 0:864a1ca8699e 162 // find precise min near an_ir_valley_locs
tenvinc 0:864a1ca8699e 163 n_exact_ir_valley_locs_count =0;
tenvinc 0:864a1ca8699e 164 for(k=0 ; k<n_npks ;k++){
tenvinc 0:864a1ca8699e 165 un_only_once =1;
tenvinc 0:864a1ca8699e 166 m=an_ir_valley_locs[k];
tenvinc 0:864a1ca8699e 167 n_c_min= 16777216;//2^24;
tenvinc 0:864a1ca8699e 168 if (m+5 < BUFFER_SIZE-HAMMING_SIZE && m-5 >0){
tenvinc 0:864a1ca8699e 169 for(i= m-5;i<m+5; i++)
tenvinc 0:864a1ca8699e 170 if (an_x[i]<n_c_min){
tenvinc 0:864a1ca8699e 171 if (un_only_once >0){
tenvinc 0:864a1ca8699e 172 un_only_once =0;
tenvinc 0:864a1ca8699e 173 }
tenvinc 0:864a1ca8699e 174 n_c_min= an_x[i] ;
tenvinc 0:864a1ca8699e 175 an_exact_ir_valley_locs[k]=i;
tenvinc 0:864a1ca8699e 176 }
tenvinc 0:864a1ca8699e 177 if (un_only_once ==0)
tenvinc 0:864a1ca8699e 178 n_exact_ir_valley_locs_count ++ ;
tenvinc 0:864a1ca8699e 179 }
tenvinc 0:864a1ca8699e 180 }
tenvinc 0:864a1ca8699e 181 if (n_exact_ir_valley_locs_count <2 ){
tenvinc 0:864a1ca8699e 182 *pn_spo2 = -999 ; // do not use SPO2 since signal ratio is out of range
tenvinc 0:864a1ca8699e 183 *pch_spo2_valid = 0;
tenvinc 0:864a1ca8699e 184 return;
tenvinc 0:864a1ca8699e 185 }
tenvinc 0:864a1ca8699e 186 // 4 pt MA
tenvinc 0:864a1ca8699e 187 for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
tenvinc 0:864a1ca8699e 188 an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int32_t)4;
tenvinc 0:864a1ca8699e 189 an_y[k]=( an_y[k]+an_y[k+1]+ an_y[k+2]+ an_y[k+3])/(int32_t)4;
tenvinc 0:864a1ca8699e 190 }
tenvinc 0:864a1ca8699e 191
tenvinc 0:864a1ca8699e 192 //using an_exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration ratio
tenvinc 0:864a1ca8699e 193 //finding AC/DC maximum of raw ir * red between two valley locations
tenvinc 0:864a1ca8699e 194 n_ratio_average =0;
tenvinc 0:864a1ca8699e 195 n_i_ratio_count =0;
tenvinc 0:864a1ca8699e 196
tenvinc 0:864a1ca8699e 197 for(k=0; k< 5; k++) an_ratio[k]=0;
tenvinc 0:864a1ca8699e 198 for (k=0; k< n_exact_ir_valley_locs_count; k++){
tenvinc 0:864a1ca8699e 199 if (an_exact_ir_valley_locs[k] > BUFFER_SIZE ){
tenvinc 0:864a1ca8699e 200 *pn_spo2 = -999 ; // do not use SPO2 since valley loc is out of range
tenvinc 0:864a1ca8699e 201 *pch_spo2_valid = 0;
tenvinc 0:864a1ca8699e 202 return;
tenvinc 0:864a1ca8699e 203 }
tenvinc 0:864a1ca8699e 204 }
tenvinc 0:864a1ca8699e 205 // find max between two valley locations
tenvinc 0:864a1ca8699e 206 // and use ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2
tenvinc 0:864a1ca8699e 207
tenvinc 0:864a1ca8699e 208 for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
tenvinc 0:864a1ca8699e 209 n_y_dc_max= -16777216 ;
tenvinc 0:864a1ca8699e 210 n_x_dc_max= - 16777216;
tenvinc 0:864a1ca8699e 211 if (an_exact_ir_valley_locs[k+1]-an_exact_ir_valley_locs[k] >10){
tenvinc 0:864a1ca8699e 212 for (i=an_exact_ir_valley_locs[k]; i< an_exact_ir_valley_locs[k+1]; i++){
tenvinc 0:864a1ca8699e 213 if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i];n_x_dc_max_idx =i; }
tenvinc 0:864a1ca8699e 214 if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i];n_y_dc_max_idx=i;}
tenvinc 0:864a1ca8699e 215 }
tenvinc 0:864a1ca8699e 216 n_y_ac= (an_y[an_exact_ir_valley_locs[k+1]] - an_y[an_exact_ir_valley_locs[k] ] )*(n_y_dc_max_idx -an_exact_ir_valley_locs[k]); //red
tenvinc 0:864a1ca8699e 217 n_y_ac= an_y[an_exact_ir_valley_locs[k]] + n_y_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]) ;
tenvinc 0:864a1ca8699e 218
tenvinc 0:864a1ca8699e 219
tenvinc 0:864a1ca8699e 220 n_y_ac= an_y[n_y_dc_max_idx] - n_y_ac; // subracting linear DC compoenents from raw
tenvinc 0:864a1ca8699e 221 n_x_ac= (an_x[an_exact_ir_valley_locs[k+1]] - an_x[an_exact_ir_valley_locs[k] ] )*(n_x_dc_max_idx -an_exact_ir_valley_locs[k]); // ir
tenvinc 0:864a1ca8699e 222 n_x_ac= an_x[an_exact_ir_valley_locs[k]] + n_x_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]);
tenvinc 0:864a1ca8699e 223 n_x_ac= an_x[n_y_dc_max_idx] - n_x_ac; // subracting linear DC compoenents from raw
tenvinc 0:864a1ca8699e 224 n_nume=( n_y_ac *n_x_dc_max)>>7 ; //prepare X100 to preserve floating value
tenvinc 0:864a1ca8699e 225 n_denom= ( n_x_ac *n_y_dc_max)>>7;
tenvinc 0:864a1ca8699e 226 if (n_denom>0 && n_i_ratio_count <5 && n_nume != 0)
tenvinc 0:864a1ca8699e 227 {
tenvinc 0:864a1ca8699e 228 an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ; //formular is ( n_y_ac *n_x_dc_max) / ( n_x_ac *n_y_dc_max) ;
tenvinc 0:864a1ca8699e 229 n_i_ratio_count++;
tenvinc 0:864a1ca8699e 230 }
tenvinc 0:864a1ca8699e 231 }
tenvinc 0:864a1ca8699e 232 }
tenvinc 0:864a1ca8699e 233
tenvinc 0:864a1ca8699e 234 maxim_sort_ascend(an_ratio, n_i_ratio_count);
tenvinc 0:864a1ca8699e 235 n_middle_idx= n_i_ratio_count/2;
tenvinc 0:864a1ca8699e 236
tenvinc 0:864a1ca8699e 237 if (n_middle_idx >1)
tenvinc 0:864a1ca8699e 238 n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median
tenvinc 0:864a1ca8699e 239 else
tenvinc 0:864a1ca8699e 240 n_ratio_average = an_ratio[n_middle_idx ];
tenvinc 0:864a1ca8699e 241
tenvinc 0:864a1ca8699e 242 if( n_ratio_average>2 && n_ratio_average <184){
tenvinc 0:864a1ca8699e 243 n_spo2_calc= uch_spo2_table[n_ratio_average] ;
tenvinc 0:864a1ca8699e 244 *pn_spo2 = n_spo2_calc ;
tenvinc 0:864a1ca8699e 245 *pch_spo2_valid = 1;// float_SPO2 = -45.060*n_ratio_average* n_ratio_average/10000 + 30.354 *n_ratio_average/100 + 94.845 ; // for comparison with table
tenvinc 0:864a1ca8699e 246 }
tenvinc 0:864a1ca8699e 247 else{
tenvinc 0:864a1ca8699e 248 *pn_spo2 = -999 ; // do not use SPO2 since signal ratio is out of range
tenvinc 0:864a1ca8699e 249 *pch_spo2_valid = 0;
tenvinc 0:864a1ca8699e 250 }
tenvinc 0:864a1ca8699e 251 }
tenvinc 0:864a1ca8699e 252
tenvinc 0:864a1ca8699e 253
tenvinc 0:864a1ca8699e 254 void maxim_find_peaks(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x, int32_t n_size, int32_t n_min_height, int32_t n_min_distance, int32_t n_max_num)
tenvinc 0:864a1ca8699e 255 /**
tenvinc 0:864a1ca8699e 256 * \brief Find peaks
tenvinc 0:864a1ca8699e 257 * \par Details
tenvinc 0:864a1ca8699e 258 * Find at most MAX_NUM peaks above MIN_HEIGHT separated by at least MIN_DISTANCE
tenvinc 0:864a1ca8699e 259 *
tenvinc 0:864a1ca8699e 260 * \retval None
tenvinc 0:864a1ca8699e 261 */
tenvinc 0:864a1ca8699e 262 {
tenvinc 0:864a1ca8699e 263 maxim_peaks_above_min_height( pn_locs, pn_npks, pn_x, n_size, n_min_height );
tenvinc 0:864a1ca8699e 264 maxim_remove_close_peaks( pn_locs, pn_npks, pn_x, n_min_distance );
tenvinc 0:864a1ca8699e 265 *pn_npks = min( *pn_npks, n_max_num );
tenvinc 0:864a1ca8699e 266 }
tenvinc 0:864a1ca8699e 267
tenvinc 0:864a1ca8699e 268 void maxim_peaks_above_min_height(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x, int32_t n_size, int32_t n_min_height)
tenvinc 0:864a1ca8699e 269 /**
tenvinc 0:864a1ca8699e 270 * \brief Find peaks above n_min_height
tenvinc 0:864a1ca8699e 271 * \par Details
tenvinc 0:864a1ca8699e 272 * Find all peaks above MIN_HEIGHT
tenvinc 0:864a1ca8699e 273 *
tenvinc 0:864a1ca8699e 274 * \retval None
tenvinc 0:864a1ca8699e 275 */
tenvinc 0:864a1ca8699e 276 {
tenvinc 0:864a1ca8699e 277 int32_t i = 1, n_width;
tenvinc 0:864a1ca8699e 278 *pn_npks = 0;
tenvinc 0:864a1ca8699e 279
tenvinc 0:864a1ca8699e 280 while (i < n_size-1){
tenvinc 0:864a1ca8699e 281 if (pn_x[i] > n_min_height && pn_x[i] > pn_x[i-1]){ // find left edge of potential peaks
tenvinc 0:864a1ca8699e 282 n_width = 1;
tenvinc 0:864a1ca8699e 283 while (i+n_width < n_size && pn_x[i] == pn_x[i+n_width]) // find flat peaks
tenvinc 0:864a1ca8699e 284 n_width++;
tenvinc 0:864a1ca8699e 285 if (pn_x[i] > pn_x[i+n_width] && (*pn_npks) < 15 ){ // find right edge of peaks
tenvinc 0:864a1ca8699e 286 pn_locs[(*pn_npks)++] = i;
tenvinc 0:864a1ca8699e 287 // for flat peaks, peak location is left edge
tenvinc 0:864a1ca8699e 288 i += n_width+1;
tenvinc 0:864a1ca8699e 289 }
tenvinc 0:864a1ca8699e 290 else
tenvinc 0:864a1ca8699e 291 i += n_width;
tenvinc 0:864a1ca8699e 292 }
tenvinc 0:864a1ca8699e 293 else
tenvinc 0:864a1ca8699e 294 i++;
tenvinc 0:864a1ca8699e 295 }
tenvinc 0:864a1ca8699e 296 }
tenvinc 0:864a1ca8699e 297
tenvinc 0:864a1ca8699e 298
tenvinc 0:864a1ca8699e 299 void maxim_remove_close_peaks(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x,int32_t n_min_distance)
tenvinc 0:864a1ca8699e 300 /**
tenvinc 0:864a1ca8699e 301 * \brief Remove peaks
tenvinc 0:864a1ca8699e 302 * \par Details
tenvinc 0:864a1ca8699e 303 * Remove peaks separated by less than MIN_DISTANCE
tenvinc 0:864a1ca8699e 304 *
tenvinc 0:864a1ca8699e 305 * \retval None
tenvinc 0:864a1ca8699e 306 */
tenvinc 0:864a1ca8699e 307 {
tenvinc 0:864a1ca8699e 308
tenvinc 0:864a1ca8699e 309 int32_t i, j, n_old_npks, n_dist;
tenvinc 0:864a1ca8699e 310
tenvinc 0:864a1ca8699e 311 /* Order peaks from large to small */
tenvinc 0:864a1ca8699e 312 maxim_sort_indices_descend( pn_x, pn_locs, *pn_npks );
tenvinc 0:864a1ca8699e 313
tenvinc 0:864a1ca8699e 314 for ( i = -1; i < *pn_npks; i++ ){
tenvinc 0:864a1ca8699e 315 n_old_npks = *pn_npks;
tenvinc 0:864a1ca8699e 316 *pn_npks = i+1;
tenvinc 0:864a1ca8699e 317 for ( j = i+1; j < n_old_npks; j++ ){
tenvinc 0:864a1ca8699e 318 n_dist = pn_locs[j] - ( i == -1 ? -1 : pn_locs[i] ); // lag-zero peak of autocorr is at index -1
tenvinc 0:864a1ca8699e 319 if ( n_dist > n_min_distance || n_dist < -n_min_distance )
tenvinc 0:864a1ca8699e 320 pn_locs[(*pn_npks)++] = pn_locs[j];
tenvinc 0:864a1ca8699e 321 }
tenvinc 0:864a1ca8699e 322 }
tenvinc 0:864a1ca8699e 323
tenvinc 0:864a1ca8699e 324 // Resort indices longo ascending order
tenvinc 0:864a1ca8699e 325 maxim_sort_ascend( pn_locs, *pn_npks );
tenvinc 0:864a1ca8699e 326 }
tenvinc 0:864a1ca8699e 327
tenvinc 0:864a1ca8699e 328 void maxim_sort_ascend(int32_t *pn_x,int32_t n_size)
tenvinc 0:864a1ca8699e 329 /**
tenvinc 0:864a1ca8699e 330 * \brief Sort array
tenvinc 0:864a1ca8699e 331 * \par Details
tenvinc 0:864a1ca8699e 332 * Sort array in ascending order (insertion sort algorithm)
tenvinc 0:864a1ca8699e 333 *
tenvinc 0:864a1ca8699e 334 * \retval None
tenvinc 0:864a1ca8699e 335 */
tenvinc 0:864a1ca8699e 336 {
tenvinc 0:864a1ca8699e 337 int32_t i, j, n_temp;
tenvinc 0:864a1ca8699e 338 for (i = 1; i < n_size; i++) {
tenvinc 0:864a1ca8699e 339 n_temp = pn_x[i];
tenvinc 0:864a1ca8699e 340 for (j = i; j > 0 && n_temp < pn_x[j-1]; j--)
tenvinc 0:864a1ca8699e 341 pn_x[j] = pn_x[j-1];
tenvinc 0:864a1ca8699e 342 pn_x[j] = n_temp;
tenvinc 0:864a1ca8699e 343 }
tenvinc 0:864a1ca8699e 344 }
tenvinc 0:864a1ca8699e 345
tenvinc 0:864a1ca8699e 346 void maxim_sort_indices_descend(int32_t *pn_x, int32_t *pn_indx, int32_t n_size)
tenvinc 0:864a1ca8699e 347 /**
tenvinc 0:864a1ca8699e 348 * \brief Sort indices
tenvinc 0:864a1ca8699e 349 * \par Details
tenvinc 0:864a1ca8699e 350 * Sort indices according to descending order (insertion sort algorithm)
tenvinc 0:864a1ca8699e 351 *
tenvinc 0:864a1ca8699e 352 * \retval None
tenvinc 0:864a1ca8699e 353 */
tenvinc 0:864a1ca8699e 354 {
tenvinc 0:864a1ca8699e 355 int32_t i, j, n_temp;
tenvinc 0:864a1ca8699e 356 for (i = 1; i < n_size; i++) {
tenvinc 0:864a1ca8699e 357 n_temp = pn_indx[i];
tenvinc 0:864a1ca8699e 358 for (j = i; j > 0 && pn_x[n_temp] > pn_x[pn_indx[j-1]]; j--)
tenvinc 0:864a1ca8699e 359 pn_indx[j] = pn_indx[j-1];
tenvinc 0:864a1ca8699e 360 pn_indx[j] = n_temp;
tenvinc 0:864a1ca8699e 361 }
tenvinc 0:864a1ca8699e 362 }
tenvinc 0:864a1ca8699e 363