How can i put the values in gradient of a function obtained through the gradient command?

Question

RADHIKA GOUR 2018-11-30

编辑： VBBV 2024-4-21

TT=[1 1 1 1];

syms p0 p1 p2 p3 p4;

f_function = log(noise+p1*TT(1)+p2*TT(2)+p3*TT(3)+p4*TT(4));

f_gradient = gradient(f_function,[p0, p1, p2, p3, p4]);

f_gradient = f_gradient.'

Here I got f_gradient function of p1,p2,p3, p4.

now i want to evaluate it by putting p0=2, p1=2,..likewise...

How can I do this.

Answer 1

VBBV 2024-4-21

编辑：VBBV 2024-4-21

@RADHIKA GOUR, you can use subs and plug-in the values for p1,p2,p3, p4 variables.

TT=[1 1 1 1];

noise = randi([2 10]);

syms p0 p1 p2 p3 p4;

f_function = log(noise+p1*TT(1)+p2*TT(2)+p3*TT(3)+p4*TT(4));

f_gradient = gradient(f_function,[p0, p1, p2, p3, p4])

f_gradient =

f_gradient = double(subs(f_gradient,{p1,p2,p3,p4},{2,2,1,4})) % give some values and use subs

f_gradient = 5x1

0 0.0714 0.0714 0.0714 0.0714