LinalgUtil (MeteoInfoLib 1.9 API)

java.lang.Object
- org.meteoinfo.math.linalg.LinalgUtil

```
public class LinalgUtil
extends Object
```
作者:

Yaqiang Wang

构造器概要

构造器
构造器说明

LinalgUtil()

构造器
构造器	说明
`LinalgUtil()`

方法概要

所有方法静态方法具体方法
限定符和类型	方法	说明
`static Array`	`cholesky(Array a)`	Calculates the Cholesky decomposition of a matrix.
`static double`	`determinantOfMatrix(double[][] mat, int n, int N)`
`static double`	`determinantOfMatrix(Array mat)`	Calculate determinant of a matrix array
`static Array[]`	`eigen(Array a)`	Calculates the eigen decomposition of a real matrix.
`static Array[]`	`eigen_bak(Array a)`	Calculates the eigen decomposition of a real matrix.
`static Array[]`	`eigen_EJML(Array a)`	Calculates the eigen decomposition of a real matrix.
`static void`	`getCofactor(double[][] mat, double[][] temp, int p, int q, int n)`
`static Array`	`inv(Array a)`	Calculate inverse matrix
`static Array`	`lstsq(Array a, Array b)`	Not correct at present !!!
`static Array[]`	`lu(Array a)`	Calculates the LUP-decomposition of a square matrix.
`static Array[]`	`qr(Array a)`	Calculates the QR-decomposition of a matrix.
`static Array`	`solve(Array a, Array b)`	Solve a linear matrix equation, or system of linear scalar equations.
`static Array[]`	`svd(Array a)`	Calculates the compact Singular Value Decomposition of a matrix.
`static Array[]`	`svd_EJML(Array a)`	Calculates the compact Singular Value Decomposition of a matrix.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - LinalgUtil
```
public LinalgUtil()
```
- 方法详细资料
  - solve
```
public static Array solve(Array a,
                          Array b)
```
    Solve a linear matrix equation, or system of linear scalar equations.
    
    参数:
    
    a - Coefficient matrix.
    
    b - Ordinate or “dependent variable” values.
    
    返回:
    
    Solution to the system a x = b. Returned shape is identical to b.
  - cholesky
```
public static Array cholesky(Array a)
```
    Calculates the Cholesky decomposition of a matrix. The Cholesky decomposition of a real symmetric positive-definite matrix A consists of a lower triangular matrix L with same size such that: A = LLT. In a sense, this is the square root of A.
    
    参数:
    
    a - The given matrix.
    
    返回:
    
    Result array.
  - lu
```
public static Array[] lu(Array a)
```
    Calculates the LUP-decomposition of a square matrix. The LUP-decomposition of a matrix A consists of three matrices L, U and P that satisfy: P×A = L×U. L is lower triangular (with unit diagonal terms), U is upper triangular and P is a permutation matrix. All matrices are m×m.
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result P/L/U arrays.
  - qr
```
public static Array[] qr(Array a)
```
    Calculates the QR-decomposition of a matrix. The QR-decomposition of a matrix A consists of two matrices Q and R that satisfy: A = QR, Q is orthogonal (QTQ = I), and R is upper triangular. If A is m×n, Q is m×m and R m×n.
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result Q/R arrays.
  - svd
```
public static Array[] svd(Array a)
```
    Calculates the compact Singular Value Decomposition of a matrix. The Singular Value Decomposition of matrix A is a set of three matrices: U, Σ and V such that A = U × Σ × VT. Let A be a m × n matrix, then U is a m × p orthogonal matrix, Σ is a p × p diagonal matrix with positive or null elements, V is a p × n orthogonal matrix (hence VT is also orthogonal) where p=min(m,n).
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result U/S/V arrays.
  - svd_EJML
```
public static Array[] svd_EJML(Array a)
```
    Calculates the compact Singular Value Decomposition of a matrix. The Singular Value Decomposition of matrix A is a set of three matrices: U, Σ and V such that A = U × Σ × VT. Let A be a m × n matrix, then U is a m × p orthogonal matrix, Σ is a p × p diagonal matrix with positive or null elements, V is a p × n orthogonal matrix (hence VT is also orthogonal) where p=min(m,n).
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result U/S/V arrays.
  - eigen_bak
```
public static Array[] eigen_bak(Array a)
```
    Calculates the eigen decomposition of a real matrix. The eigen decomposition of matrix A is a set of two matrices: V and D such that A = V × D × VT. A, V and D are all m × m matrices.
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result W/V arrays.
  - eigen
```
public static Array[] eigen(Array a)
```
    Calculates the eigen decomposition of a real matrix. The eigen decomposition of matrix A is a set of two matrices: V and D such that A = V × D × VT. A, V and D are all m × m matrices.
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result W/V arrays.
  - eigen_EJML
```
public static Array[] eigen_EJML(Array a)
```
    Calculates the eigen decomposition of a real matrix. The eigen decomposition of matrix A is a set of two matrices: V and D such that A = V × D × VT. A, V and D are all m × m matrices.
    
    参数:
    
    a - Given matrix.
    
    返回:
    
    Result W/V arrays.
  - inv
```
public static Array inv(Array a)
```
    Calculate inverse matrix
    
    参数:
    
    a - The matrix
    
    返回:
    
    Inverse matrix array
  - lstsq
```
public static Array lstsq(Array a,
                          Array b)
```
    Not correct at present !!!
    
    参数:
    
    a -
    
    b -
    
    返回:
  - getCofactor
```
public static void getCofactor(double[][] mat,
                               double[][] temp,
                               int p,
                               int q,
                               int n)
```
  - determinantOfMatrix
```
public static double determinantOfMatrix(double[][] mat,
                                         int n,
                                         int N)
```
  - determinantOfMatrix
```
public static double determinantOfMatrix(Array mat)
```
    Calculate determinant of a matrix array
    
    参数:
    
    mat - Input array
    
    返回:
    
    Determinant

类 LinalgUtil

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

LinalgUtil

方法详细资料

solve

cholesky

lu

qr

svd

svd_EJML

eigen_bak

eigen

eigen_EJML

inv

lstsq

getCofactor

determinantOfMatrix

determinantOfMatrix