Interpolation

Choose interpolation when your signal members have individual timestamps that vary with each member. Interpolation resamples members to a uniformly sampled data grid.

  • Signal — Signal to interpolate.

  • Interpolation Method — For information on interpolating to a uniform grid, see the Interpolation Method section of interp1.

  • Sampling frequency — The default auto setting calculates the mean sampling frequency across all members.

The software stores the results of the computation in a new variable. The new variable name includes the source signal name with the suffix interp.

Use interpolation only if you can consider your signals to be concurrent. If you use signals that are intentionally staggered in start time, interpolation expands each member signal from its original size to the full length of the entire sequence using NaN fill. For example, suppose that you want to maintain a sequence of three different measurement days. Each day has the same amount of data and sampling frequency, but each has a different start time. Grid interpolation expands each data member from one day to three days. This signal expansion and NaN handling increase processing overhead and slows computation.

For more information on gridded interpolation, see Interpolating Gridded Data (MATLAB).