Linear Approximation

• If you have a plot of points on a 2D chart, you can calculate a best fit line through them.
• This is linear approximation.
• If the line is a good fit, given a y (or an x) you can calculate the x (or y).
• With the points, if you have the y, you can get the x.
• You can use linear regression to solve for a line, or other more sophisticated methods to derive more complex functions as approximators.
• One way to do it is to plot the points on a graph, and eye ball it (people are pretty good at this).
• Another way is to minimize the mean square error.
• If the mean error is small, it's a good fit.
• Look at the simple linear reqression wiki for a formula.