Linear interpolator help

Troubleshooting interpolator

The interpolator is implemented in JavaScript. If you do not have JavaScript enabled in your browser, the form will not work.

The x input values must be unique and the y values must be unique. This means the same number cannot appear twice in the x column or twice in the y column.

Exactly one box must be empty before clicking the Calculate button.

Interpolation derivations

A straight line through (x₁, y₁) and (x₂, y₂) satisfies

To see why this is true, stick in x₁ and x₂ and see that you get y₁ and y₂ out. If a linear fit is correct at two different points, it's correct everywhere.

So if we set x equal to x₃, then

Solving for x₃ we see that