infinite line that works with pan, zoom and auto-scale

infiniLine adds an infinite line to a plot, similar to a grid-line

infiniLine adds an infinite line to a plot. The line will always extend to the axes boundaries, even after changing the limits or interactive zoom and pan. The infiniLine does not interfere with auto-scale. Two files are required, infiniLine.m contains the function to add the line, infiniLineCallBack.m contains the callback function that is called when the plot is updated.