# correlation of 2 signals

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ali hassan on 28 Nov 2020
Commented: Image Analyst on 28 Nov 2020
Actually I am corelating two signals but my question is that in graph the correlation should be between -1 and 1 but it is not like that code:
t=linspace(0,1000,100001) %in ms xs=randn(1,100001)
grid on
subplot(3,1,1) plot(t,xs) title('SIGNAL RECEIVED AT MASTER')
[c,lags]=xcorr(xs,x1);
subplot(3,1,3)
plot(lags,c)
title('CORRELATION OF RECEIVER 1 AND PROCESSING UNIT')
[maxval indx]=max(c) %[xMax,idx] = max(x) returns two outputs.first is max value of x and second is max index value maxval
shiftCalc_ms = (length(t)-indx)/10
t21 = finddelay(xs,x1)

KALYAN ACHARJYA on 28 Nov 2020
Edited: KALYAN ACHARJYA on 28 Nov 2020
clc; clear;close all;
%%
t=linspace(0,1000,100001); %in ms
xs=randn(1,100001);
subplot(3,1,1),plot(t,xs);
shift_ms = 10; %SIGNAL RECEIVED AT RECEIVER 1(TIME DELAYING THE DISCRETE SIGNAL)
subplot(3,1,2)
[c,lags]=xcorr(xs,x1);
subplot(3,1,3),plot(c,lags)
title('CORRELATION OF RECEIVER 1 AND PROCESSING UNIT')
[maxval,indx]=max(c);
[xMax,idx] = max(xs);
shiftCalc_ms=(length(t)-indx)/10;
t21=finddelay(xs,x1);
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Image Analyst on 28 Nov 2020
The correlation is the sum of the products of the overlapped elements, so there is no guarantee that that sum will be between 0 and 1. If you want it to be in that range, then you must call rescale():
scaledSignal = rescale(signal, 0, 1);