Finding multiple x values in plot for given y
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Geroge Papas
on 17 Dec 2020
Answered: Geroge Papas
on 17 Dec 2020
I have to find the values for x when y=0 but i cant seem to make it work. I have tried with interp1 but it seems that it gives me an answer of x=2.3490 which is clearly wrong,since there are 2 points in the plot where y=0. Here's the code:
x = [0:0.001:pi]
f = exp(x/4).*sin(x)-1;
plot(x,f)
xlabel('Axis x');
ylabel('Axis y');
newLim = get(gca,'XLim');
newx = linspace(newLim(1), newLim(2), 30);
set(gca,'XTick', newx);
% what I tried:
yi = 0 ;
xi = interp1(f,x,yi) ;
hold on
semilogy(xi,yi,'*r')
Accepted Answer
More Answers (1)
Daniel Pollard
on 17 Dec 2020
I think you want fsolve. Give it a function handle and an initial starting point, and it'll tell you (approximately) what x gives f(x)=0.
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