Interpolation allows you to add new data
points between pairs of existing data points, while extrapolation
allows you to add data points that extend beyond the beginning
or ending values of your data range.
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Interpolation
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Extrapolation
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There are two different tools that can perform interpolation and extrapolation operations in Origin: Interpolate/Extrapolate and Interpolate/Extrapolate Y from X. Both tools support the following 3 methods to interpolate/extrapolate the data:
- Linear
- Cubic Spline
- Cubic B-Spline
The Interpolate/Extrapolate tool can be opened by selecting Analysis: Mathematics Interpolate/Extrapolate from the Origin menu. It allows you to specify the X minimum, X maximum and the number of points of the interpolated/extrapolated curve. Origin then generates the X dataset and the corresponding Y dataset of the result curve.

Interpolate/Extrapolate Dialog
The Interpolate/Extrapolate Y from X tool can be opened by selecting Analysis: Mathematics Interpolate/Extrapolate Y from X from the Origin menu. It allows you to choose an existing dataset as the X dataset of the result curve. Then the interpolated/extrapolated Y values corresponding to the X dataset will be calculated.

Interpolate/Extrapolate Y from X Dialog
Origin includes the ability to automatically recalculate the analysis results of the interpolation and extrapolation operations any time you change the parameters or update your source data. In addition, the settings for this analysis routine can be saved to an analysis theme for later use with similar data.