How can i make a training of square pulse to neural network ? how
2 views (last 30 days)
Show older comments
mahmoud shojaee
on 22 Jan 2015
Commented: mahmoud shojaee
on 24 Jan 2015
when i am training a square wave to a neural network ,network reply response below
</matlabcentral/answers/uploaded_files/24263/111.JPG> figure 1 : response of training of network ; figure 2: square pulse train ; why don't have same network's response and pulse train? code: fs = 100000 t = 0:1/fs:5; x2 = square(2*pi*t); net = newff([-1.5 1.5],[5,1],{'logsig','purelin'}); net= train(net,t,x2); Y=net(x2); subplot(211) plot(t,Y) axis([0 5 -1.2 1.2]);
subplot(212) plot(t,x2)
1 Comment
Greg Heath
on 23 Jan 2015
Edited: Greg Heath
on 23 Jan 2015
Reformat so that the program will run when cut and pasted into the command line
Accepted Answer
Greg Heath
on 23 Jan 2015
% when i am training a square wave to a neural network , network reply response below % /matlabcentral/answers/uploaded_files/24263/111.JPG
% figure 1 : response of training of network ;
% figure 2: square pulse train ;
% why don't have same network's response and pulse train?
% code:
fs = 100000
t = 0:1/fs:5;
N = length(t) % 500,001
x2 = square(2*pi*t); % 0 <= 2*pi*t <= 31.416
net = newff([-1.5 1.5],[5,1],{'logsig','purelin'});
0. I don't have a toolbox with the square function. Therefore, I used x2 = sign(sin(2*pi*t))
1. You are trying to use a half of a million points to model a non-differentiable square wave over 5 periods.
2. For a sine wave
a. As few as ~12 points per period may be sufficient
b. At least 2 hidden node sigmoids are needed for each peak
3. You erroneously entered the input range to be [-1.5 1.5] instead of [ 0 5 ].
Hope this helps.
*Thank you for formally accepting my answer*
Greg
3 Comments
Greg Heath
on 23 Jan 2015
Dr. Heath or Prof. Heath. However, I prefer Greg.
Label your plots Target and Output, respectively. Also increase the vertical range on the lower plot.
Greg
More Answers (0)
See Also
Categories
Find more on Sequence and Numeric Feature Data Workflows in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!