finding x and y intercept
57 views (last 30 days)
Show older comments
Hi i want to ask something. How do I find the x and y intercepts of a function using gui
here is my code
funcString = get(handles.edit1,'String');
funcHandle = str2func(['@(x)' funcString]);
x = linspace(100,-100,200);
y = funcHandle(x);
plot(handles.axes1,x,y);
the function is user defined
0 Comments
Accepted Answer
LeoAiE
on 23 Apr 2023
I think you can first calculate the x-intercepts by checking for sign changes in the y values, then using fzero to find the exact root. We store the x-intercepts in the x_intercepts variable. Next, we evaluate the function at x = 0 to find the y-intercept and store it in the y_intercept variable.
Finally, we display the x and y-intercepts in the GUI by setting the 'String' property of text elements handles.x_intercepts_text and handles.y_intercept_text, respectively. We also add markers for the intercepts on the plot.
Please note that you'll need to add the text elements x_intercepts_text and y_intercept_text to your GUI for displaying the intercepts. You can do this using MATLAB's GUIDE or App Designer.
% Your existing code
funcString = get(handles.edit1,'String');
funcHandle = str2func(['@(x)' funcString]);
x = linspace(-100, 100, 200);
y = funcHandle(x);
plot(handles.axes1, x, y);
% Find x-intercept(s)
x_intercepts = [];
tol = 1e-6; % Tolerance for identifying unique roots
for i = 1:length(x) - 1
if y(i) * y(i + 1) <= 0
root = fzero(funcHandle, [x(i), x(i + 1)]);
if isempty(x_intercepts) || min(abs(x_intercepts - root)) > tol
x_intercepts = [x_intercepts, root];
end
end
end
% Find y-intercept
y_intercept = funcHandle(0);
% Display the results
set(handles.x_intercepts_text, 'String', sprintf('X-Intercepts: %s', mat2str(x_intercepts, 4)));
set(handles.y_intercept_text, 'String', sprintf('Y-Intercept: %.4f', y_intercept));
% Add intercepts to the plot
hold(handles.axes1, 'on');
plot(handles.axes1, x_intercepts, zeros(size(x_intercepts)), 'ro');
plot(handles.axes1, 0, y_intercept, 'bo');
hold(handles.axes1, 'off');
2 Comments
More Answers (0)
See Also
Categories
Find more on Line Plots in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!