Solving an integral with variable as upper limit and plotting the solution
10 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
How can I solve an integral when the upper limit is a variable, and then plot the solution? My integral is as follows: Integral of e^(-(y^2))dy and my upper limit is x, while the lower limit is negative infinity. X and y are variables. I have tried using the trapz function, but then you must have a constant as upper limit. I have also tried using the int-funtion, but that is only solving for an indefinite integral. Does anyone know what I should do?
0 Commenti
Risposta accettata
Torsten
il 20 Gen 2015
Your function is equal to
sqrt(pi)/2*(1+erf(x))
Best wishes
Torsten.
1 Commento
john zhang
il 12 Ago 2020
what if the function is very complex and has no general antiderivative? Thank you
Più risposte (4)
David
il 20 Gen 2015
4 Commenti
John D'Errico
il 21 Gen 2015
You could just use basic calculus.
erf gives you the integral from 0 to x. If you want the integral from -inf to x, then add 1. This is because the integral from -inf to 0 is 1.
erf(-inf)
ans =
-1
(Beware of the order of those limits, which gives me here -1.)
So the integral from -inf to x is
1 + erf(x)
Which is valid for any real x as your upper limit.
Vedere anche
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!