Slice of a surface plot created by 2D data

Hi, I have been trying to create a slice though my surface plot which is created with stacked 2D data.

Fs = 3000;
tspan = 0 : 1/Fs :15;

topt = 3
j = topt-1.0 : 0.05 : topt+4.0
---------------------------------------------------------------

delta_r1 = zeros(length(tspan), length(j));
delta_r2 = zeros(length(tspan), length(j));
for ii = 1:numel(j)
    t_THz = j(ii);
    delta_r1(:,ii) = Fourier1P - fourier1P(:,ii); 
    delta_r2(:,ii) = Fourier2P - fourier2P(:,ii); 
end

delay = zeros(1,length(j));
for ii = 1:numel(j)
    t_THz = j(ii);
    delay(ii) = t_THz - topt;
end

yMat = repmat(delay, numel(tspan),1);
xMat = repmat(F1.',1,length(j));

plot3(xMat,yMat,delta_r1)
xlim([358 362.5])
zlim([-0.4e-4 2e-4])
xlabel('Frequency (THz)','Rotation', -15)
ylabel('Delay (ps)','Rotation', 23)
title('x_1(f)')
view([19.245913 34.150412])
figure
surf(xMat,yMat,delta_r1)   
xlim([358.5 361.7])
zlim([-0.4e-4 2e-4])
xlabel('Frequency (THz)','Rotation',-15)
ylabel('Delay (ps)','Rotation',23)
view([40.018393 23.670967])
colormap(jet)  
shading interp

where

delta_r1

and

delta_r2

are 2D arrays of size 45001×101.

I want to create a slice though x = 360.9 so that I can get the side view of the oscillation.

I am tryging to do something like this: https://stackoverflow.com/questions/38342244/how-can-i-create-a-slice-of-a-surface-plot-to-create-a-line-matlab

What I have now is this:

x = linspace(358,362.5,length(tspan))
delay

[X,Y] = meshgrid(x,delay)
yq = linspace(-1,4,101)
xq = linspace(360.9,360.9,101)
zq = interp2(X,Y,delta_r1',xq,yq);
dq = sqrt((xq-360.9).^2 + (yq+1).^2);
plot(dq,zq)
axis([min(dq),max(dq),-0.4e-4,2e-4]) 

I get this plot

It's a straight line rather than an oscillation.

Does anyone know how to fix it?

[Thiago Henrique Gomes Lobato]

The problem may be in your interpolation function since you're attributing different position values to your calculated results. You may try something like this:

zq = interp2(xMat,yMat,delta_r1,xq,yq);
dq = sqrt((xq-360.9).^2 + (yq+1).^2);
plot(dq,zq)

Answer 1

[Rajani Mishra]

You can try using function “slice()”, refer to this link for more information : https://www.mathworks.com/help/matlab/ref/slice.html#d118e1325646. Also I found a similar question here : https://www.mathworks.com/matlabcentral/answers/488992-how-to-take-a-horizontal-slice-of-a-3d-surface-plot