Hi, I want the tolerance around this figure, I have posted the code ,where i am getting two figures on the upper and lower halfs of the original figure, which is shown in the attached image.Can anyone tell me what changes i must do ?

I have attached two figures

1. Error1.jpeg (which shows two figures on upper and lower half according to the code i posted)

2. correct.jpeg (This is how the figure should look like ,i want it to be projected on top of the original figure)

Here are the images

And here is the code :

file = 'idle_coil_for_imag_real.xlsx' ;
[num,txt,raw]  = xlsread(file) ;
imag = num(:,2) ;
real = num(:,1) ;
%plot(real,imag,'*')
%[xx,yy] = pol2cart(x,y);
k = convhull(real, imag);
xch = real(k);
ych = imag(k);
%[xCH, yCH] = cart2pol(xch, ych);
plot(xch, ych, 'ro-','LineWidth', 1);
hold on
plot(real,imag,'b*','LineWidth', 1);
%plot(xch, ych, 'ro-',real,imag,'b*');
xlabel('real');
ylabel('imag');
title('IDLE','FontSize',10);
hold on
% Plot lines for a tolerance band above and below the perfect signal.
tolerance = 0.1; % Whatever you want.
yUpperLimit = ych + tolerance;
yLowerLimit = ych - tolerance;
xUpperLimit = xch + tolerance;
xLowerLimit = xch - tolerance;
plot(xUpperLimit, yUpperLimit, 'g.-', 'LineWidth', 1, 'MarkerSize', 14, 'Color', [0, 0.5, 0]);
plot(xLowerLimit, yLowerLimit, 'g.-', 'LineWidth', 1, 'MarkerSize', 14, 'Color', [0, 0.5, 0]);

Answer 1

[Walter Roberson]

You have

tolerance = 0.1; % Whatever you want.
yUpperLimit = ych + tolerance;

0.1 is large compared to your values, so you are shifting the plotting a fair bit.

One approach would be to find the centroid of your signal, and then calculate the difference in coordinates between that and your boundary points. Convert to polar. Multiply the radius by 1.1 and convert back. Add to the centroid to get the new boundary. Likewise, you can multiply the radius by 0.9 instead of 1.1.

[L K]

Could you tell me how i will find centroid of this? The function present is to find centroid of image.I dont want to find of image,

How can i find it ?

[Walter Roberson]

mean() of all of the x coordinates will give the x component of the centroid; mean() of all of the y coordinates will give the y component of the centroid.

[L K]

Thanx :)

[L K]

hi,

I tried doing what you said, but not getting the result,

Here is the code:

file = 'data_ironnut.xlsx' ;
[num,txt,raw]  = xlsread(file) ;
phase = num(:,2) ;
amp = num(:,1) ;
%theta=[-60,-59,-58,-57,-52,-54,-55,-56,-57,110,109,108,109,110,109,111,115,120];
%radius=[4,6,8,12,19,23,26.5,26,21,11,0,12,22,26.5,23,19,12,8];
theta_rad = phase * pi/180;
%theta_rad = phase ;
polar(theta_rad, amp, 'b*');
hold on;
[x, y] = pol2cart(theta_rad, amp);
k = convhull(x, y);
xch = x(k);
ych = y(k);
[thetaCH1, rhoCH1] = cart2pol(xch, ych);
%subplot(212)
polar(thetaCH1, rhoCH1, 'ro-');

meanX=mean(xch);
meanY=mean(ych);

difference_xch= xch(:)-meanX ;
difference_ych= ych(:)-meanY ;

difference_polar=cart2pol(difference_xch,difference_ych);

new_difference_xch=difference_xch*0.9;
new_difference_ych=difference_ych;

add_new_difference_xch=new_difference_xch+meanX;
add_new_difference_ych=new_difference_ych+meanY;

%polar(add_new_difference_amp, add_new_difference_theta_rad, 'g.-', 'LineWidth', 1, 'MarkerSize', 14, 'Color', [0, 0.5, 0]);
polar(add_new_difference_xch, add_new_difference_ych,'o');

[Walter Roberson]

Attached code that draws the +/- 0.1 around the data in polar space

[L K]

Thanx a lot Sir :) Its done :)