MATLAB: Fill comand (functions)

fill comand areas

how can i fill just this area in matlab? i need help.

Best Answer

Try this:
x = linspace(-5, 5);                                        % Define Indepenent Variable
upgoing_curve = x.^2;                                       % Define First Curve
downgoing_curve = 5 - x.^2;                                 % Define Second Curve
idx = (downgoing_curve > upgoing_curve) & (x >= 0);         % Define Region-Of-Interest
figure(1)
plot(x, upgoing_curve,    x, downgoing_curve, '-k');
hold on
patch([x(idx) fliplr(x(idx))], [upgoing_curve(idx) fliplr(downgoing_curve(idx))], 'g')
hold off
The patch call defines the independent variable and then flips it, and the dependent variables and flips the second one. The idea here is to create a closed curve, defined by ‘x(idx)’ and its ‘mirror image’, and the lower curve and the flipped version of the upper curve.
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