Le 03/02/2023 à 20:57, Samuel Gougeon a écrit : .../... Here is a draft proposal: 1) build the (let's say row) vector A = (dPHI/dt) of sampled data at sampled values t 2) build the row vector B = f(-t) of sample data at t values 3) build the matrix C of (padded) A and the matrix D of (shiffted and padded) D = B(T-t), with T as multiples of the dt step Each row of C and D corresponds to a T value. 4) compute E = (C .* D)*dt when dt is the time step. 5) Set to zero all elements on (#) and above the diagonal of E. That's to cancel elements with t>T, to code the upper bound T of the integral. 5) sum E along rows (the actual integration. You can refine with a trapeze method).
and that's it: the resulting column vector is your F(T). As you know the formal expressions of f() and of phi(t), the other way is to use intg() in a for loop over T, leading to something like this: m = 2; // Weibull modulus in mechanism #1 k = 1E-7; // corrosion rate(s-1) in mechanism #1 function r = pseudoconv(t, T) r = 3600*m*k*((k*t)^(m-1)) * exp(-((k*t)^m)) * (1 - exp((T+t)/3E5)); endfunction n = 500; dT = 5; F = zeros(1, n); T = (0:(n-1))*dT; for i = 1:n F(i) = intg(0, T(i), pseudoconv); end Samuel This email and any attachments are intended solely for the use of the individual or entity to whom it is addressed and may be confidential and/or privileged. If you are not one of the named recipients or have received this email in error, (i) you should not read, disclose, or copy it, (ii) please notify sender of your receipt by reply email and delete this email and all attachments, (iii) Dassault Systèmes does not accept or assume any liability or responsibility for any use of or reliance on this email. Please be informed that your personal data are processed according to our data privacy policy as described on our website. Should you have any questions related to personal data protection, please contact 3DS Data Protection Officer https://www.3ds.com/privacy-policy/contact/
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