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Max and Min of matlab function

Asked by KYLE ALVAREZ on 21 Oct 2019 at 20:41
Latest activity Commented on by KYLE ALVAREZ on 22 Oct 2019 at 1:11
This is my code to create a function. I have looked over many of the other questions regarding the max and min of a function and I keep getting error codes for max function and get function. This is my basic function:
f = @(r) (150.*(((1 + r).^36)-1) - 4500.*(r.*(1 + r).^36));
t = fplot(f,[0.0001 0.02]);
t
I have tried:
y = get(t,'YData');
imin = find(min(y) == y);% find the index of the min and max
imax = find(max(y) == y);
and it does not work. Any help is appreciated! Thank you!

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1 Answer

Answer by Stephan
on 21 Oct 2019 at 20:52
 Accepted Answer

f = @(r) (150.*(((1 + r).^36)-1) - 4500.*(r.*(1 + r).^36));
t = fplot(f,[0.0001 0.02]);
high = max(t.YData)
low = min(t.YData)

  3 Comments

KYLE ALVAREZ on 21 Oct 2019 at 21:26
Thank you! One more questions if it is no problem, how would I put that as a point on the graph? I am new to MATLAB and have this code so far but cannot seem to put the hard point on it.
text(0.004,1,"Y Maximum = 2.592")
text(0.014,-25,"Y Minimum = -27.6068")
Stephan
on 22 Oct 2019 at 0:36
f = @(r) (150.*(((1 + r).^36)-1) - 4500.*(r.*(1 + r).^36));
t = fplot(f,[0.0001 0.02]);
[high, idh] = max(t.YData);
[low, idl] = min(t.YData);
hold on
scatter([t.XData(idl), t.XData(idh)], [low, high], 'or')
text(0.004,1,"Y Maximum = 2.592")
text(0.014,-25,"Y Minimum = -27.6068")
hold off
KYLE ALVAREZ on 22 Oct 2019 at 1:11
Thank you!

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