how to find short path on graph

hello I have a directed graph with many streams shown in the picture, so I try to solve this problem using graph theory in MATLAB but even very simple code on graph does not work I use R2015a, for using graph or digraph I got the error : Undefined function or variable 'digraph'. the points of the graph arranged as x,y, the first and last points are start and goal respectively thank you in advance for any help 30 10 30 191 30 10 45 206 30 191 45 206 45 206 155 206 155 206 170 191 155 206 170 11 170 191 170 11

[Star Strider]

The digraph function was introduced in R2015b.

[Hazim Nasir]

thank you, I have to upgrade