Adding EMG Signal With 50Hx Sinosoidal wave. Not getting it correct

Start Time =0.00025, time interval=0.00025 and end time=12.715

I have loaded emg signal of above specified time and adding it to 50Hz noise (sinosoidal Signal), but not getting it correctly, please reply

Thanks in Advance

emg = load('emg_healthy.txt');
figure(1);
subplot(3,3,1);
plot(emg(:,1), emg(:,2));
title('original EMG Signal');
t=0.00025:0.00025:12.715;
freqNoise = 50;   
amplNoise =0.0025;  
myNoise  = amplNoise.*sin(2*pi.*t.*freqNoise);
[a b]=size(emg);
myNoisetransp=transpose(myNoise);
[u v]=size(myNoisetransp)
   for j=1:(b-v)
      myNoisetransp(:,j+1)=0;
   end

subplot(3,3,2);
plot(t,myNoise);
title('50HZ Sinosoidal PL Noise');
noisysig=emg+myNoisetransp;
subplot(3,3,3);
plot(t,noisysig);
title('EMG+PL Noise');

Graph is generated but sinosoidal wave is not overlapped with EMG Signal

Answer 1

[Christoph F.]

What is the scale of

emg(:,2)

myNoise may have a different scale than emg(:, 2) and become too small to display once the two signals are added.

[Amit jha]

The Amplitude range of EMG varies from -0.5140 to 1.1133.

Please help

[Amit jha]

this is the problem, when i am adding sinosoidal signal with emg signal, emg is separeted as green and sinosoidal as blue, Refer in figure titled EMG+PL Noise and help on basis of above code

Thanks in advance

[Christoph F.]

noisysig=emg+myNoisetransp;
plot(t,noisysig);

emg has (at least) two columns, with time information in the first column (emg(:, 1)) and voltage information in the second column (emg(:, 2)).

To add the generated noise to the emg voltage column, try

noisysig = emg(:, 2) + myNoisetransp;

(The jpg shows two vectors being plotted in the third graph: the emg voltage vector in green, and the time vector plus added noise in blue.)