convert symbols to variables

Hi everyone,

I can find the partial derivative of a function using syms:

syms x , d
f = ... % a complicated function of x and d
df = diff(f,d)

I would like now to use x and d as variables in a for loop to calculate df for specific values of x and d. How is this possible? Thank you!

Answer 1

[Azzi Abdelmalek]

syms x  d
f = x*sin(d) 
df=diff(f,d)
d1=pi
x1=5
out=subs(df,[d x],[d1 x1])

[Goldy]

great! thank you! well, what if I want to do something like this:

    for x=0:0.1:5
       for d=0:20
           ...
       end
    end

What would I put instead of

d1=pi
x1=5
out=subs(df,[d x],[d1 x1])

?

[Azzi Abdelmalek]

k=0;
for x1=0:0.1:5
     for d1=0:20
         k=k+1;
         out(k)=subs(df,[d x],[d1 x1])
     end
end