Here is the link to a file I corrected from a user posted on the forum (file attached)
http://en.smath.info/forum/yaf_postsm12734_2D-plot-with-multiple-variables.aspx#post12734
If I try to use the original y vector of 10^9 order of magnitude crash happened. Plotting will cause this.
Please try to reproduce. Here is the video file made on my computer
http://screencast-o-matic.com/watch/c2fjopnOo2