Real function for symbolic variables

why does

>>real(2+3*i)

give me an error message while

>> imag(2+3*i)
ans =
     3

works?

Answer 1

[the cyclist]

What error message do you get? Neither of those commands gives an error for me. Might you have redefined the real() command somehow? Does

 >> which real

give the expected file location? (It should be a built-in function in the elfun directory structure.)

Answer 2

[Walter Roberson]

2+3*i would not inherently involve the symbolic toolbox, not unless you have overwritten "i" with a symbolic variable.

Is the 2+3*i perhaps a value that you had returned from a symbolic calculation without using double(), and is thus sym('2+3*i') ?

Answer 3

[David Koenig]

Thanks for the responses, the cyclist and Walter Roberson. I think my problem had to do with not declaring the variables properly in a syms statement. I have since been more careful and have resolved the issues - and using 2011a instead of 6.1 has made a pleasant difference.