====== Interpolate ======

The Interpolate command fills in any gaps in a signal's data using a spline interpolation. This can be useful if there are unreliable data points ([[visual3d:documentation:c3d_signal_types:target_data_type#target_marker_residuals|residuals]] < 0).

The interpolation procedure performs a least-squares fit of an nth order polynomial to k data points.

<code>
|(x1,t1),...,(xk,tk)|k >= polynomial order + 1|
</code>

The command is given in text form as:
<code>
Interpolate
/SIGNAL_TYPES=
! /SIGNAL_NAMES=
! /SIGNAL_FOLDER=ORIGINAL
! /RESULT_SUFFIX=
! /RESULT_FOLDER=PROCESSED
/MAXIMUM_GAP=
! /NUM_FIT=3
! /POLYNOMIAL_ORDER=3
;
</code>

{{:InterpolateDlg2.jpg}}

===== Parameters =====

^ Parameter ^ Description ^
| /Signal_Types | The type of signal to be processed. |
| /Signal_Names | The names of the signals to be processed. |
| /Signal_Folder | The name of the signal folder. |
| /Num_Fit | The number of frames of data before and after the "gap" that are used to calculate the coefficients of the polynomial. |
| /Polynomial_Order | The order of the polynomial used. |
| /Maximum_Gap | The maximum number of frames of data that can be replaced with interpolated values. |

===== Example: Using an expression =====

Define the maximum size of the gap based on the POINT frame rate.

{{:InterpolateDlg3.jpg}}