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Interpolate Matrix(x,y)

Return interpolated matrix for given inputs

  • Library:
  • Aerospace Blockset / GNC / Control

  • Interpolate Matrix(x,y) block

Description

The Interpolate Matrix(x,y) block interpolates a two-dimensional array of matrices. In two-dimensional cases, the interpolation is carried out first on x and then y. For more information, see Algorithms.

The matrix to be interpolated must be four-dimensional, the first two dimensions corresponding to the matrix at each value of x and y. For example, if you have four matrices A, B, C, and D defined at (x = 0.0,y = 1.0), (x = 0.0,y = 3.0), (x = 1.0,y = 1.0) and (x = 1.0,y = 3.0), then the input matrix is given by

matrix(:,:,1,1) = A;

matrix(:,:,1,2) = B;

matrix(:,:,2,1) = C;

matrix(:,:,2,2) = D;

Limitations

This block must be driven from the Prelookup block.

Ports

Input

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First interpolation index i, specified as a scalar and vector.

Data Types: double

First interpolation fraction λ x, specified as a scalar

Data Types: double

Second interpolation index j, specified as a scalar.

Data Types: double

Second interpolation fraction λ y, specified as a scalar.

Data Types: double

Output

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Interpolated matrix, specified as a matrix.

Data Types: double

Parameters

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Matrix to be interpolated, with four indices and the third and fourth indices labeling the interpolating values of x and y.

Programmatic Use

Block Parameter: matrix
Type: character vector
Values: matrix
Default: 'matrix'

Algorithms

This two-dimensional case assumes the matrix is defined as a function of two independent variables, x = [ x1x2x3... xixi+1 ... xn] and y = [ y1y2y3 ... yjyj+1 ... ym]. For given values of x and y, four matrices are interpolated. Then for xi < x < xi+1 and yj < y < yj+1, the output matrix is given by

(1λy)[(1λx)M(xi,yj)+λxM(xi+1,yj)]+λy[(1λx)M(xi,yj+1)+λxM(xi+1,yj+1)]

where the two interpolation fractions are denoted by

λx=(xxi)/(xi+1xi)

and

λy=(yyj)/(yj+1yj)

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Introduced before R2006a