1. Linear interpolation 1.1. Purpose Interpolate a signal against a lookup table. 1.2. Description The linear interpolation function uses a lookup table and linear interpolation to find corresponding values. Extrapolation is not supported by the linear interpolation. A typical application would be to interpolate moment time-series using a non-linear lookup table to find stress time-series to be used in fatigue analysis or code-check. In this case the lookup table will consist of two columns containing moment and corresponding stress. You can choose between matching with the y-axis or the x-axis of the input. 1.3. Input Equidistant and non-equidistant signals (see Signal Types ) are supported. The lookup table must contain values in increasing order on the matching axis and should cover the range of the input signal to avoid extrapolation.. 1.4. Output Signals which have been linearly interpolated against the lookup table.