wenchang fei / Mbed OS mbed-os-example-peak-test

the first vision of peak detection. I try to detect the value max of a array that the previous min point is lower than a threshold given.

main.cpp@0:08dd14677b02, 2019-11-20 (annotated)

Committer:
castlefei
Date:
Wed Nov 20 11:56:33 2019 +0000
Revision:
0:08dd14677b02
peak detection by wenchang Fei

Who changed what in which revision?

UserRevisionLine numberNew contents of line
castlefei 0:08dd14677b02 1 /* mbed Microcontroller Library
castlefei 0:08dd14677b02 2 * Copyright (c) 2019 ARM Limited
castlefei 0:08dd14677b02 3 * SPDX-License-Identifier: Apache-2.0
castlefei 0:08dd14677b02 4 */
castlefei 0:08dd14677b02 5
castlefei 0:08dd14677b02 6 #include "mbed.h"
castlefei 0:08dd14677b02 7 #include "platform/mbed_thread.h"
castlefei 0:08dd14677b02 8 #include <vector>
castlefei 0:08dd14677b02 9 #include <iostream>
castlefei 0:08dd14677b02 10
castlefei 0:08dd14677b02 11 // Blinking rate in milliseconds
castlefei 0:08dd14677b02 12 #define BLINKING_RATE_MS 500
castlefei 0:08dd14677b02 13 using namespace std;
castlefei 0:08dd14677b02 14
castlefei 0:08dd14677b02 15 void findPeaks(float *num,int count, float threshold)
castlefei 0:08dd14677b02 16 {
castlefei 0:08dd14677b02 17 vector<int> sign;
castlefei 0:08dd14677b02 18 for(int i = 1;i<count;i++)
castlefei 0:08dd14677b02 19 {
castlefei 0:08dd14677b02 20 /*do difference between the near points：
castlefei 0:08dd14677b02 21 *result<0，sign = -1
castlefei 0:08dd14677b02 22 *result>0，sign = 1
castlefei 0:08dd14677b02 23 *result=0，sign = 0
castlefei 0:08dd14677b02 24 */
castlefei 0:08dd14677b02 25 int diff = num[i] - num[i-1];
castlefei 0:08dd14677b02 26 if(diff>0)
castlefei 0:08dd14677b02 27 {
castlefei 0:08dd14677b02 28 sign.push_back(1);
castlefei 0:08dd14677b02 29 }
castlefei 0:08dd14677b02 30 else if(diff<0)
castlefei 0:08dd14677b02 31 {
castlefei 0:08dd14677b02 32 sign.push_back(-1);
castlefei 0:08dd14677b02 33 }
castlefei 0:08dd14677b02 34 else
castlefei 0:08dd14677b02 35 {
castlefei 0:08dd14677b02 36 sign.push_back(0);
castlefei 0:08dd14677b02 37 }
castlefei 0:08dd14677b02 38 }
castlefei 0:08dd14677b02 39 //do difference between the near sign
castlefei 0:08dd14677b02 40 //result < 0 save the max index
castlefei 0:08dd14677b02 41 //result > 0 save the min index
castlefei 0:08dd14677b02 42 vector<int> indMax;
castlefei 0:08dd14677b02 43 vector<int> indMin;
castlefei 0:08dd14677b02 44 int cnt = 1;
castlefei 0:08dd14677b02 45 for(int j = 1;j<sign.size();j++)
castlefei 0:08dd14677b02 46 {
castlefei 0:08dd14677b02 47 int diff = sign[j]-sign[j-1];
castlefei 0:08dd14677b02 48 if(diff<0)
castlefei 0:08dd14677b02 49 {
castlefei 0:08dd14677b02 50 indMax.push_back(j);
castlefei 0:08dd14677b02 51 }
castlefei 0:08dd14677b02 52 else if(diff>0)
castlefei 0:08dd14677b02 53 {
castlefei 0:08dd14677b02 54 indMin.push_back(j);
castlefei 0:08dd14677b02 55 }
castlefei 0:08dd14677b02 56 }
castlefei 0:08dd14677b02 57 //try to find the valid max (which the previous min is smaller than threshold)
castlefei 0:08dd14677b02 58 //begin with index 1 so there will have +1 or -1 error
castlefei 0:08dd14677b02 59 for(int j = 1;j<indMax.size();j++)
castlefei 0:08dd14677b02 60 {
castlefei 0:08dd14677b02 61
castlefei 0:08dd14677b02 62 for(int i =0; i <indMin.size()-1; i++)
castlefei 0:08dd14677b02 63 {
castlefei 0:08dd14677b02 64 if(indMin[i]<indMax[j] && indMin[i+1]>indMax[j] && num[indMin[i]]< threshold)
castlefei 0:08dd14677b02 65 {
castlefei 0:08dd14677b02 66 cnt = cnt +1;
castlefei 0:08dd14677b02 67 printf("found a valid max, index:%d, value: %f \n\r", indMax[j],num[indMax[j]]);
castlefei 0:08dd14677b02 68 }
castlefei 0:08dd14677b02 69 }
castlefei 0:08dd14677b02 70
castlefei 0:08dd14677b02 71 }
castlefei 0:08dd14677b02 72 printf("num of max: %d\n\r", indMax.size());
castlefei 0:08dd14677b02 73 printf("num of valid max: %d\n\r", cnt);
castlefei 0:08dd14677b02 74
castlefei 0:08dd14677b02 75 cout<<"max values:"<<endl;
castlefei 0:08dd14677b02 76 for(int m = 0;m<indMax.size();m++)
castlefei 0:08dd14677b02 77 {
castlefei 0:08dd14677b02 78 cout<<num[indMax[m]]<<" ";
castlefei 0:08dd14677b02 79 }
castlefei 0:08dd14677b02 80 cout<<endl;
castlefei 0:08dd14677b02 81 cout<<"min values："<<endl;
castlefei 0:08dd14677b02 82 for(int n = 0;n<indMin.size();n++)
castlefei 0:08dd14677b02 83 {
castlefei 0:08dd14677b02 84 cout<<num[indMin[n]]<<" ";
castlefei 0:08dd14677b02 85 }
castlefei 0:08dd14677b02 86 cout<<endl;
castlefei 0:08dd14677b02 87 }
castlefei 0:08dd14677b02 88
castlefei 0:08dd14677b02 89 int main()
castlefei 0:08dd14677b02 90 {
castlefei 0:08dd14677b02 91 // Initialise the digital pin LED1 as an output
castlefei 0:08dd14677b02 92 DigitalOut led(LED1);
castlefei 0:08dd14677b02 93 float a[] = {1,2,10,2,4,0,8,10,23,0,2, 0, 5};
castlefei 0:08dd14677b02 94 int len = sizeof(a)/sizeof(int);
castlefei 0:08dd14677b02 95 while (true) {
castlefei 0:08dd14677b02 96 //printf("len of a is %d \n\r", len);
castlefei 0:08dd14677b02 97 findPeaks(a,len,1);
castlefei 0:08dd14677b02 98 led = !led;
castlefei 0:08dd14677b02 99 thread_sleep_for(BLINKING_RATE_MS);
castlefei 0:08dd14677b02 100 }
castlefei 0:08dd14677b02 101 }