%Wireless sensors for continuous, multimodal measurements at the skin interface with lower limb prostheses
%MATLAB code to identify the cycle.

%Jean Kwak, Mengdi Han
%2020

clear;clc;
close all


%% set threshold
threshold = 50;
min_peak_height = 200;  
min_peak_distance = 0.3;

%% import data
figure(1);
fid = fopen('data.txt');
data = textscan(fid, '%f %f');
fclose(fid);
pressure = data{2};
pressure = pressure(~isnan(pressure));
time = data{1};
time = time(~isnan(pressure));
time = time-time(1);
plot(time,pressure);
title('raw data');

%% find voltage drops
figure(2);
[pks1,locs1] = findpeaks(-pressure,time,'ThresHold',threshold);
hold on
plot(time,pressure);
scatter(locs1,-pks1);
title('find voltage drops');

%% define cycle
figure(3);
[pks2,locs2] = findpeaks(pressure,time,'MinPeakHeight',min_peak_height,'MinPeakDistance',min_peak_distance);
hold on
plot(time,pressure);
scatter(locs1,-pks1);
scatter(locs2,pks2);
title('define cycle');