hdl.interpn

Find interpolated value based on n-dimensional input data

Since R2024b

Syntax

Vq = hdl.interpn(X1,X2,...,Xn,V,Xq1,Xq2,...,Xqn)

Vq = hdl.interpn(X1,X2,...,Xn,V,Xq1,Xq2,...,Xqn,interpolation,extrapolation)

Description

Vq = hdl.interpn(X1,X2,...,Xn,V,Xq1,Xq2,...,Xqn) returns the interpolated values of a function of n variables at a specific query point using linear interpolation and linear extrapolation. X1,X2,...,Xn contain the coordinates of the sample points in each dimension. V contains the corresponding function values at each sample point. Xq1,Xq2,...,Xqn contain the coordinates of the query point.

Vq = hdl.interpn(X1,X2,...,Xn,V,Xq1,Xq2,...,Xqn,interpolation,extrapolation) also specifies interpolation and extrapolation approximation methods.

Examples

1-D Interpolation

Define the sample points and values.

X = [1 2 3 4 5];
V = [12 16 31 10 6];

Define the query point, Xq, and find the interpolated value for this point.

Xq = 4.3;
Vq = hdl.interpn(X,V,Xq);

Vq 
= 8.8000;

4-D Interpolation

Define the sample points and values. Initialize the random number generator by using the default generator algorithm and seed. For more information, see rng.

X1 = 1:30; X2 = -10:10; X3 = 1:5; X4 = 10:13;
rng("default");
V = rand(30,21,5,4);

Define the query point, Xq, and find the interpolated value for this point.

Xq1 = 35; Xq2 = 20; Xq3 = 10; Xq4 = 1;
Vq = hdl.interpn(X1,X2,X3,X4,V,Xq1,Xq2,Xq3,Xq4,"linear","nearest");

Vq 
= 0.7811;

Input Arguments

X1,X2,...,Xn — Sample points

arrays | vectors

Sample points, specified as real arrays or vectors. The sample points within each argument must be unique.

Example: [X1,X2,X3,X4] = [1:30,-10:10,1:5,10:13]

Data Types: single | double

V — Sample values

array

Sample values, specified as a real array. The dimensions of V must be the same as sizes of the sample point arrays X1,X2,...,Xn.

Example: rand(10,5,3,2)

Data Types: single | double

Xq1,Xq2,...,Xqn — Coordinates of query point

scalars

Coordinates of query point, specified as real scalars.

Example: [Xq1,Xq2,Xq3,Xq4] = [35 20 10 1]

Data Types: single | double

interpolation — Interpolation method

"linear"

Interpolation method, specified as "linear".

Data Types: char | string

extrapolation — Extrapolation method

"linear" | "nearest"

Extrapolation method, specified as "linear" or "nearest".

Data Types: char | string

Output Arguments

Vq — Interpolated value

scalar

Interpolated value, returned as a real scalar.

Extended Capabilities

HDL Code Generation

Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

The approximation methods supported for code generation are "linear" for interpolation, and "linear" and "nearest" for extrapolation.

For code generation, the hdl.interpn function does not support:

• Fixed-point data type

• Multiple query points

Version History

Introduced in R2024b