Borrar filtros
Borrar filtros

Finding x-intercept in a 2d plot shown below, there are multiple loops I want to find all the values of X at Y=0...Please help..

6 visualizaciones (últimos 30 días)
gowtham balu
gowtham balu el 13 de Dic. de 2022
Comentada: Star Strider el 14 de Dic. de 2022
I have a 2D plot and I want to find x-intercept(x at y=0) for all the loops shown in the figure attached. Anyone please post relevant command and how can i use it in matlab.
If there is 2D raw data required I can share that too.
Thanks everyone.

Iniciar sesión para responder a esta pregunta.

Respuestas (2)

Torsten
Torsten el 13 de Dic. de 2022
If you have the x-y values as vectors available, you can use this code to determine the x-values where y=0:
i = find(y(1:end-1).*y(2:end) <= 0)
x_root = x(i)-y(i).*(x(i+1)-x(i))./(y(i+1)-y(i))
Star Strider
Star Strider el 13 de Dic. de 2022
Ran in:
Something like this should work —
%Finding X value with known Y value on plot
t = linspace(0, 2*pi, 1000); % Create Data
ph = -rand(10,1);
x = cos(2*pi*t*5 + zeros(size(ph)));
y = sin(2*pi*t*5 + ph);
x = reshape(x.',[],1);
y = reshape(y.',[],1);
figure
plot(x, y)
grid
axis('padded')
zxi = find(diff(sign(y))); % Indices Of Approximate Y-Zero-Crossings
for k = 1:size(zxi)
idxrng = max(1,zxi(k)-1) : min(numel(x),zxi(k)+1);
xv(k,:) = interp1(y(idxrng), x(idxrng), 0);
% yv(k,:) = interp1(x, ABC(k,:), xv(k,:));
end
xv
xv = 639×1
0.7099 -0.7088 0.7080 -0.7074 0.7071 -0.7072 0.7074 -0.7080 0.7088 -0.7100
% yv
figure
plot(x, y, 'DisplayName', 'Original Data')
hold on
plot(xv, zeros(size(xv)), '+r', 'DisplayName', 'X-Intersections')
hold off
grid
legend('Location','eastoutside')
axis('padded')
This uses synthetic data. It detects all the y-vector zero-crossings and returns the corresponding x-values in ‘xv’, and plots them.
It should work with your data without alteration, although it will require that you assign the appropriate values to ‘x’ and ‘y’ in my code.
.
  5 comentarios
Mostrar 3 comentarios más antiguos
gowtham balu
gowtham balu el 14 de Dic. de 2022
I humbly Thank you for your speedy and timely response and answers........
With regards,
Gowtham

Iniciar sesión para comentar.

Categorías

Más información sobre Line Plots en Help Center y File Exchange.

Etiquetas

Productos


Versión

R2015a

Community Treasure Hunt

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

Start Hunting!

Translated by