Table Of Contents

Matrix Logarithm (G Dataflow)

Version:
    Last Modified: March 15, 2017

    Computes the natural logarithm of a square matrix.

    connector_pane_image
    datatype_icon

    matrix

    A square matrix.

    This input accepts a 2D array of double-precision, floating point numbers or 2D array of complex double-precision, floating point numbers.

    datatype_icon

    logarithm option

    Option for the logarithm that this node returns.

    Name Value Description
    General 0 Regards the input matrix as a complex matrix.
    Real 1 Returns an exact real logarithm when the input matrix is a non-singular normal matrix and each of the negative eigenvalues occur an even number of times. When the input matrix is not normal or one of its negative eigenvalues occurs an odd number of times, this node returns the matrix logarithm as if logarithm option was General.

    Default: General

    datatype_icon

    error in

    Error conditions that occur before this node runs.

    The node responds to this input according to standard error behavior.

    Standard Error Behavior

    Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

    error in does not contain an error error in contains an error
    If no error occurred before the node runs, the node begins execution normally.

    If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

    If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

    Default: No error

    datatype_icon

    matrix logarithm

    The natural logarithm of the input matrix.

    datatype_icon

    error out

    Error information.

    The node produces this output according to standard error behavior.

    Standard Error Behavior

    Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

    error in does not contain an error error in contains an error
    If no error occurred before the node runs, the node begins execution normally.

    If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

    If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

    Algorithm for Calculating the Logarithm of a Matrix

    The natural logarithm is the inverse operation of the exponential. The following equation defines the natural logarithm of a matrix A:

    e B = A

    where

    • matrix B is the logarithm of matrix A.

    A matrix has a logarithm if and only if its inverse matrix exists. For a real matrix A, its logarithm matrix B can be complex, and the conjugate of matrix B is also the natural logarithm of matrix A.

    A real matrix A is normal if AAT = ATA.

    For a non-singular normal matrix, if each negative eigenvalues of matrix A occur an even number of times, matrix A has a real logarithm. Note that this does not guarantee the uniqueness of the real logarithm.

    Where This Node Can Run:

    Desktop OS: Windows

    FPGA: This product does not support FPGA devices


    Recently Viewed Topics