How does this equation create this chart? 
I am trying to understand this formula from the chart above.
For example, from the middle graph, How does h(x) = 0.5x get the coordinates 2,1?
Any explanations on the other graphs would be helpful, too.
Edit:  How would I find theta 0 and theta 1 given the following graph?


The horizontal axis is for values of $x$ and the vertical one is for the values of a function $h_{\theta}(x)$. So if we have $h_{\theta}(x)=\theta_0+\theta_1x$ where $\theta_0=0$ and $\theta_1=0,5$ than you have the function $h_{\theta}(x)=0+0,5x=0,5x$ and for $x=2$ you have  h_{\theta}(2)=0,5*2=1$ so if in the horizontal axis we take value 2 in the vertical one we get value 1. Thats how we get the coordinate (2,1).
