Computing the Jacobian of vectorized ODEs in MATLAB -

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this works fine:

syms b x jacobian ([a*x - a*b, a*b],[a, b])

but this:

syms b(i) x = 1:6 jacobian ([a*x - a*b(i), a*b(i)],[a, b(i)])

returns error:

error using sym/jacobian (line 37) second argument must vector of variables.

in opinion second argument is vector of variables don't understand error.

is possible differentiate respect vector of odes e.g. b(i)? how go it?

the declaration syms b(i) creates symbolic function b of i. so, if vector of doubles passed b(i), output vector of function values:

>> syms b(i) >> b(1:6) ans = [ b(1), b(2), b(3), b(4), b(5), b(6)]  >> b(i) = i^2;  % defining actual function generate actual values >> b(1:6) ans = [ 1, 4, 9, 16, 25, 36]

so error correct: have list of values. create vector of variables, use sym function

>> b = sym('b',[1,6]) b = [ b1, b2, b3, b4, b5, b6]

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