Halcon knowledge: matrix topic [01]

One 、 summary     

        This article talks about Halcon The matrix operation of . When doing some experiments , Often use matlab convenient , Actually , be familiar with halcon Of scholars , Also available halcon Realize the routine mathematical experiment . I think halcon It is a very rich resource , Even more than Opencv, Specialized in extrusion time research halcon The matrix is a very accounting effort .

Two 、 Matrix correlation operator

2.1 How to create a matrix

 create_matrix( : : Rows, Columns, Value : MatrixID)

Parameter table ：( : : Rows- Number of matrix lines , Columns- Number of matrix columns , Value- Matrix element value tuple : MatrixID- Matrix index number )

explain ： Here you create the matrix , It is required to pass all elements of the matrix into , The format for 1X（rows*columns） dimension .

Rows:=4
Cols:=4
Value:=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
create_matrix(Rows,Cols,Value,MatrixID )

2.2 Reading of matrix elements

get_value_matrix( : : MatrixID, Row, Column : Value)

Parameter table ：( : : MatrixID-- The index number of the matrix , Row-- use tuple Specified multiline , Column-- use tuple Specified multiple columns : Value-- use tuple Specified output )

              Another situation , If only one value is accessed , that Row, Column Just give it in the form of quantity

explain ： The reference sample

1） Access a value  

get_value_matrix(  MatrixID, 5, 7 ,Value)    *Value gain 5 That's ok 7 The value of the column

2） Accessing multiple values

2.3 Get matrix size

get_size_matrix(matrix_id,rows,cols)

2.4  Create a diagonal matrix or get the diagonal elements of the matrix

         Operator get_diagonal_matrix Generate a new matrix Vector And will Matrix The diagonal elements of are copied to this new matrix . A matrix consists of a matrix handle MatrixID Definition . A matrix vector has a column sum n That's ok , among n = The number of diagonal elements . Operator returns matrix Vector Matrix handle for VectorID. You can access the elements of the matrix , For example, use the operator .

1 For squares

The diagonals of the square matrix have the th 0、-1、1、-2、2... Geru ：

 2 Non square matrix

2.5 Get all the elements of the matrix

• get_full_matrix(MatrixID, Values)

Get all the elements of the matrix ：

 2.6 Get the submatrix of the matrix

• get_sub_matrix( : : MatrixID, Row, Column, RowsSub, ColumnsSub : MatrixSubID)

obtain MatrixID Matrix , With Row, Column Start unit , RowsSub Row , ColumnsSub Submatrix of columns .

2.7 Set matrix element values

• set_value_matrix(matrix_1_id,1,1,-10)

         This sentence will matrix matrix_1_id Of 1 That's ok 1 The column is assigned the value -10

2.8 Set the value of the entire matrix element

• set_full_matrix(matrix_1_id,1)

         This sentence takes the entire matrix matrix_1_id The element is refreshed to 1.

2.9 Inverse matrix

• invert_matrix( : : MatrixID, MatrixType, Epsilon : MatrixInvID)

Operator invert_matrix The calculation is performed by the matrix handle MatrixID The inverse of a defined matrix . Use the results to generate a new matrix MatrixInv, And return the matrix handle of the matrix MatrixInvID. It can be used get_full_matrix Access the elements of the matrix .

about Epsilon = 0, Count the reciprocal . Can pass MatrixType choice Matrix The type of . The following values are supported ：“general” In general ,“symmetric” Indicates symmetry ,“positive_defined” Denotes symmetric positive definite ,“tridiagonal” Represents a three diagonal line ,“upper_triangular” Represents the upper triangle ,“permuted_upper_triangular” Represents the upper triangle of the displacement ,“lower_triangular” For lower triangular matrix ,'permuted_lower_triangular' For permutation of lower triangular matrix .

about Epsilon > 0, Using singular value decomposition (SVD) Compute pseudo inverse . During calculation , All less than Epsilon * The singular values of the maximum singular value are all set to 0. For these values , No internal division to prevent division by zero . If you use SVD The algorithm calculates the square matrix , It takes more time to calculate . The type of the matrix must be set to MatrixType = 'general'.

2.10 Take the inverse of the matrix

invert_matrix_mod

Operator invert_matrix_mod The calculation is performed by the matrix handle MatrixID The inverse of a defined matrix .

The input matrix is covered by the result . You can access the elements of the matrix , For example, use the operator get_full_matrix.

Other contents are the same as invert_matrix.