isdag(biograph), problem with matrix input.

Hello, am beginner with matLab, hope you will help me.
I have to make a simple program with input, which will look for cycles in directed graph.

here is my code:

syms matrix;
matrx = eye([3, 3]);
matrix=input('input your matrix');
isdag(matrix);

for example my input:

input your matrix[1 0 0;0 1 0;0 1 1];

here is my error:

??? Undefined function or method 'isdag' for input arguments of type 'double'.

Error in ==> Untitled at 4
isdag(matrix);
 
I need to create biograph and test it with this function isdag (biograph).I tried to change argument type from double to int, but im having same error.Sorry for bad english.