How to cut off part of the figure out after you filtered it

Hello, I'm trying to cut out part of my plot but I dont know how I could modify the script to cut it out and here is what I got so far after I apply a lowpass filter.

Thank you for your time

 Ts = 0.01;
  Fs = 1/Ts;
  Fm = Fs/2;
  Fc = 2;
  N =10;
  d = fdesign.lowpass('N,Fc',N,Fc,Fs);
  designmethods(d);
  Hd = design(d);
   %fvtool(Hd)
   %X is a variable form csv
   %X1 is a variable from csv
   output = filter(Hd,X);
   output1 = filter(Hd,X1);
   figure;
   plot(X,X1,'-g');
   hold on
   plot(output, output1,'r');
   hold off
   legend('raw signal','filtered signal')
   xlabel('SWA (deg)')
   ylabel('SWT (N.m)')
   title('SWA vs SWT')
   grid on
   
figure

subplot(2,1,1)
plot(X,X1);
title('Original plot');
uiwait(msgbox('Select an x-value from which to crop','modal'));
[x_user ~] = ginput(1); % Let the user select an x-value from which to crop.
x(x>x_user) = [];
subplot(2,1,2);
plot(output, output1);
title('New plot with cropped values');
xlim([min(x(:)) max(x(:))]);

Answer 1

[Image Analyst]

You could just display from 100 on:

xlim([100, max(output1)]);

or you could remove everything less than x=100

startingIndex = find(x >= 100, 1, 'first');
output = output(startingIndex : end);
output1 = output1(startingIndex : end);
X = X(startingIndex : end);
X1 = X1(startingIndex : end);

Of course you could use max(x_user) instead of 100 if you want.

[nam bui]

I'm sorry, it won't work on my plot. Do you have any alternative way?

[Image Analyst]

No. But it should work. GIve your complete code so I can run it. Your code does not define X and so it does not run.

[nam bui]

load sample.mat
X = sample.current;
X1 = sample.voltage;
Ts = 0.01;
  Fs = 1/Ts;
  Fm = Fs/2;
  Fc = 2;
  N =10;
  d = fdesign.lowpass('N,Fc',N,Fc,Fs);
  designmethods(d);
  Hd = design(d);
   %fvtool(Hd)
   %X is a variable form csv
   %X1 is a variable from csv
   output = filter(Hd,X);
   output1 = filter(Hd,X1);
   figure;
   plot(X,X1,'-g');
   hold on
   plot(output, output1,'r');
   hold off
   legend('raw signal','filtered signal')
   xlabel('SWA (deg)')
   ylabel('SWT (N.m)')
   title('SWA vs SWT')
   grid on
figure
startingIndex = find(x >= 100, 1, 'first');
output = output(startingIndex : end);
output1 = output1(startingIndex : end);
X = X(startingIndex : end);
X1 = X1(startingIndex : end);

[nam bui]

the last 5 lines are straight from yur suggestion

[Image Analyst]

I'm still waiting for you to attach 'sample.mat'. I'll check back later.

Note: MATLAB is case sensitive. You've used both x and X, and those would be separate variables in MATLAB in your original code snippet:

subplot(2,1,1)
plot(X,X1);
title('Original plot');
uiwait(msgbox('Select an x-value from which to crop','modal'));
[x_user ~] = ginput(1); % Let the user select an x-value from which to crop.
x(x>x_user) = [];
subplot(2,1,2);
plot(output, output1);
title('New plot with cropped values');
xlim([min(x(:)) max(x(:))]);

So make your capitalization correct and repost your code and .mat file.

[nam bui]

load sample.mat
X = sample.current;
X1 = sample.voltage;
Ts = 0.01;
  Fs = 1/Ts;
  Fm = Fs/2;
  Fc = 2;
  N =10;
  d = fdesign.lowpass('N,Fc',N,Fc,Fs);
  designmethods(d);
  Hd = design(d);
   %fvtool(Hd)
   %X is a variable form csv
   %X1 is a variable from csv
   output = filter(Hd,X);
   output1 = filter(Hd,X1);
   figure;
   plot(X,X1,'-g');
   hold on
   plot(output, output1,'r');
   hold off
   legend('raw signal','filtered signal')
   xlabel('SWA (deg)')
   ylabel('SWT (N.m)')
   title('SWA vs SWT')
   grid on
   figure
x = output;
y = output1;
subplot(2,1,1)
plot(x,y,'r');
title('Original plot');
uiwait(msgbox('Select an x-value from which to crop','modal'));
[x_user ~] = ginput(1); % Let the user select an x-value from which to crop.
x(x>x_user) = [];
subplot(2,1,2);
plot(x,y,'r');
title('New plot with cropped values');
xlim([min(x(:)) max(x(:))]);

[nam bui]

please let me know, what should I fix, I have attached the mat file. Thank you

[Image Analyst]

Look, sample.mat does not have a "current" variable stored in it.

sample = load('sample.mat')

sample =

struct with fields:

sample: [1500×2 table]

Reference to non-existent field 'current'.

Error in test6 (line 10)

X = sample.current;

You need to use a .mat file that has both current and sample variables in it.