'subs' problem in r2013

I want to substitute a vector into an equation.

For example,

-------------------

x=1:2;

syms X

Y=X.^2;

y=subs(Y,X,x)

-------------------

Matlab 2012 or previous version gives

y =

     1     4

as a 'double' vector.

However, Matlab 2013 gives

y =

[ 1, 4]

as a 'symbolic' vector.

In order to obtain the same result as the first one,

the function 'eval' should be used in r2013.

I don't know why they give different results.

If a scalar is substituted instead of a vector,

They give the same results as a scalar.

Answer 1

[Walter Roberson]

Giving a double vector back was arguably wrong and inconsistent. Any time you work with the symbolic toolbox you should expect the result to be symbolic.

If you have a symbolic vector and you want the numeric equivalent, do not use eval(): instead use double()

double(y)