3.5.1.1.24 InterpInterp-func
Description
Minimum Origin Version Required: 2015 SR0
This function is used to perform 1D interpolation or extrapolation on a group of XY data to find Y at the given X value using 4 alternative methods.
Syntax
double Interp( double x, vector vx, vector vy [, int method=0,
int bound=1, double smooth=0, int extrap=0])
Parameters
x
- The x coordinate for finding interpolated/extrapolated y coordinate.
vx
- The source x coordinates used for interpolation.
vy
- The source y coordinates used for interpolation.
method
- Interpolation methods, supported value 0 (linear, default), 1 (cubic spline), 2 (cubic B-spline), 3 (Akima spline).
bound
- Boundary condition only available in cubic spline method, supported value 0 (Natural), 1 (Not-A-Knot, default).
smooth
- A non-negative parameter that specifies the smoothness of the interpolated curve in Cubic B-Spline interpolation.
extrap
- Controls how to extrapolate Y values when X values are outside the reference X range, supported value 0 (default value, extrapolate Y using the last two points), 1 (set all Y values in the extrapolated range to be missing values), 2 (use the Y value of the closest input X value for all values in the extrapolated range).
Return
Return the interpolated/extrapolated value y coordinate at specified x coordinate.
Example
newbook;
worksheet -a 2;
col(a)={0:0.5:10};
col(b)=sqrt(10*col(a)-col(a)^2);
col(c)={0:0.2:5};
col(d)=Interp(col(c),col(a),col(b),1,0,1);
See Also
Integrate,
IntegrateXY
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