Description:
Get cubic spline interpolation.
Syntax:
splinemthd(x,y,newx)
Note:
External library function (See External Library Guide).
x,y are a coordinate vector of an existing point, and newx is a query point vector. The function returns the interpolation vector corresponding to the query point specified by newx; the vector’s value is determined by x and y’s cubic spline interpolation values.
Parameter requirements:
1. The range of newx must not exceed the original boundaries of x;
2. x should be strictly monotonic increasing, but no requirements for y; x and y should have same length;
3. Null values and infinite values are not allowed.
Parameter:
x/y/newx |
A one-dimensional sequence. |
Return value:
Sequence
Example:
|
A |
|
1 |
=[1.0,3.0,4.0,8.0,12.0] |
|
2 |
=[3.0,5.0,7.0,15.0,21.0] |
|
3 |
=[2.0,5.0,7.0,9.0,10.0] |
|
4 |
=splinemthd(A1,A2,A3) |
|