Can someone differentiate interpolation from extrapolation?

Question

Can someone differentiate interpolation from extrapolation?

Answer 1

The best I can do is give you an example from image processing.



A bitmap image is row upon row of dots in a grid. Each dot is called a pixel.



If I am making an image smaller, I am interpolating it. Each square grouping of 4 pixels are averaged and the average color is used to fill the area that was previously taken by the 4 pixels.



If I am making an image larger. I am extrapolating on the known data. Each single pixel is divided into 4 and their colors are "guessed" by examining the colors of the surrounding pixels.



Where interpolation is absolutely accurate, a reduction of the available data, extrapolation involves considering data that wasn't part of the original equation.

Answer 2

interpolation is constructing new data points from a discrete set of known data points. extrapolation is constructing new data points from outside a discrete set of know data points.

Answer 3

Interpretation - in between



Extrapolation - extension beyond.