HARK version 1.1.0 Document : CMMultiplyEachElement

6.2.7 CMMultiplyEachElement

Module Overview

Performs component-wise multiplication of two sound source correlation matrices.

Requested Files

None.

Usage

In what case is the node used?

The calculation node of the correlation matrix is the one created for the sound source from CMMakerFromFFT , CMMakerFromFFTwithFlag , and has the function of multiplying each component.

Typical Examples

Figure. 6.16 shows the usage example of CMMultiplyEachElement node.

The CMA input terminal is connected to a correlation matrix calculated from CMMakerFromFFT or CMMakerFromFFTwithFlag , etc. (type is Matrix<complex<float> > type, but to handle a correlation matrix, convert the three dimensional complex array to a two dimensional complex array and then output). Like CMA, the CMB input terminal also connects to the correlation matrix. At the time of multiplication, CMA $.*$ CMB is calculated, where $.*$ shows component-wise multiplication. OPERATION_FLAG is int type, or bool type input, and controls when the correlation matrix multiplication is calculated.

$\includegraphics[width=100mm]{fig/modules/CMMultiplyEachElement.eps}$

Figure 6.16: Network Example using CMMultiplyEachElement

I/O and property setting of the node

Table 6.20: Parameter list of CMMultiplyEachElement

Parameter	Type	Default	Unit	Description
NB_CHANNELS	`int`	8		Number of channels $M$ of input signal
LENGTH	`int`	512		Frame length $NFFT$
FIRST_FRAME_EXECUTION	`bool`	false		Selection of the first frame execution
ENABLE_DEBUG	`bool`	false		ON/OFF of debugging information output

Input

CMA: Matrix<complex<float> > type. A correlation matrix for each frequency bin. The $M$ -th order complex square array correlation matrix inputs $NFFT/2 + 1$ items. Matrix<complex<float> > contains rows corresponding to frequencies ( $NFFT/2 + 1$ rows), and columns containing the complex correlation matrix ( $M * M$ columns across).
CMB: Matrix<complex<float> > type. Same as CMA.
OPERATION_FLAG: int type or bool type. Only when this input terminal is 1 or when true, calculation of the correlation matrix is performed.

Output

OUTPUTCM: Matrix<complex<float> > type. The correlation matrix equivalent to CMA $.*$ CMB after multiplication is output.

Parameter

NB_CHANNELS: int type. Number of channels for input signal. Equivalent to the order of the correlation matrix. Must match with the former correlation matrix used. Default value is 8.
LENGTH: int type. Default value is 512. FFT points at the time of Fourier transform. Must be matched with the former FFT length values.
FIRST_FRAME_EXECUTION: bool type. Default value is false. When true, OPERATION_FLAG is always 0. Even when it is false, the operation is performed only on first frame.
ENABLE_DEBUG: bool type. Default value is false. When true, output the frame number calculated to the standard output,during correlation matrix division.

Module Description

Performs component-wise multiplication of each component of the two correlation matrices. Note that it is not a matrix multiplication of the correlation matrix (Refer to CMMultiplyMatrix for matrix multiplication). The correlation matrix is a complex three-dimensional array of size $k \times M \times M$ and the multiplication $k \times M \times M$ times is performed as follows. Here, $k$ is the number of frequency bins ( $k = NFFT/2 + 1$ ), and $M$ is the number of channels in the input signal.

=- OUTPUTCM = zero_matrix(k,M,M) calculate{ IF OPERATION_FLAG FOR i = 1 to k FOR i = 1 to M FOR i = 1 to M OUTPUTCM[i][j][k] = CMA[i][j][k] * CMB[i][j][k] ENDFOR ENDFOR ENDFOR ENDIF }

The matrix that is output from the OUTPUTCM terminal is initialized as a zero matrix, and maintains the final operational result from this point onward.