Filter löschen
Filter löschen

Finding x intercept for 2D data

56 Ansichten (letzte 30 Tage)
University
University am 24 Nov. 2023
Beantwortet: Pavan Sahith am 12 Dez. 2023
Hi,
Please how can i find x intercept at y=0 for 2D array. For instance, I have V which is loop over xi=0:1:10 and l=0:0.1:1.
I want to find V(xi, l)=x-intercept and plot the intercepts.
  1 Kommentar
Catalytic
Catalytic am 26 Nov. 2023
If your V is a function of xi and l, then what is meant by the "x-intercept at y=0"? Is l supposed to be the same as y? xi the same as x?

Melden Sie sich an, um zu kommentieren.

Antworten (1)

Pavan Sahith
Pavan Sahith am 12 Dez. 2023
Hello,
I understand that you are working with a 2D array and would like to identify all the x-intercepts at y=0 and plot them.
You can do that in MATLAB using the "find(diff(sign('your_data')))" and "interp1" refer to this code with the consideration of sample 2D arrays.
  • Considered using sine and cosine functions to generate 2D arrays,as there will be multiple intersections with the x-axis
% Creating sample Data
t = linspace(0, 2*pi, 1000);
ph = -rand(10,1);
x = cos(2*pi*t*5 + zeros(size(ph)));
y = sin(2*pi*t*5 + ph);
  • reshaping the matrices x and y into column vectors
x = reshape(x.',[],1);
y = reshape(y.',[],1);
  • "y0 = find(diff(sign(y)))";: Finds the indices where the sign of y changes, which corresponds to approximate zero-crossings.
  • The code then uses a for loop to iterate over the identified zero-crossings (y0) and performs linear interpolation (interp1) around each zero-crossing to estimate the x-values where y is zero.
  • xv(k,:) = interp1(y(idxrng), x(idxrng), 0);: Interpolates the x-values at y=0 for each identified zero-crossing. The result is stored in the matrix xv.
y0 = find(diff(sign(y)));
for i = 1:size(y0)
idxrng = max(1, y0(i)-1) : min(numel(x),y0(i)+1);
xv(i,:) = interp1(y(idxrng), x(idxrng), 0);
end
% Plotting
plot(x, y, 'DisplayName', 'Original Data')
hold on
plot(xv, zeros(size(xv)), '+r', 'DisplayName', 'X-Intersections')
hold off
grid
legend('Location','eastoutside')
Please refer to the following MathWorks documentation to know more about
Hope that helps.

Kategorien

Mehr zu 2-D and 3-D Plots finden Sie in Help Center und File Exchange

Produkte


Version

R2023a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by