Rank: Newbie
Groups: Registered
Joined: 23/03/2019(UTC) Posts: 4 Location: SPb
|
So, I`ve tried to adopt Smath file Jean Giraud showed, but have some issues.I`m truing to fit function f(x,Ni) el(x,1)*(Ni)^el(x,2)+el(x,3)*(Ni)^el(x,4)) to experimental points: Ni:mat(729,1000,3000,10000,30000,100000,6,1) ε_res:mat(1.9996,1.6798,1.0557,0.7854,0.6741,0.6046,6,1), where Ni- number of full cycles till rupture, ε_res,- strain range. The issue is, that in your examples derivatives are functions of one variable, but in case of my one it is function of 2 variables, for example, derivative by el(x,2) is el(x,1)*(Ni)^el(x,2)*ln(Ni). Could you please give me an advise, how to fit this function, Pure Newton`s method doesn`t give me convergence. Thank you in advance.
|