splinemthd()

Read(213) Label: spline, interpolation,

Description:

Get cubic spline interpolation.

Syntax:

splinemthd(x,y,newx)

Note:

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)