Matrix Product
Multiply matrix elements along rows, columns, or entire input
Library
Math Functions / Matrices and Linear Algebra / Matrix Operations
dspmtrx3
Description
The Matrix Product block multiplies the elements of an MbyN input matrix u along its rows, its columns, or over all its elements.
When the Multiply over parameter is set to
Rows
, the block multiplies across the elements of each row and
outputs the resulting Mby1 matrix. The block treats
lengthN unoriented vector input as a 1byN
matrix.
$$\left[\begin{array}{ccc}{u}_{11}& {u}_{12}& {u}_{13}\\ {u}_{21}& {u}_{22}& {u}_{23}\\ {u}_{31}& {u}_{32}& {u}_{33}\end{array}\right]\Rightarrow \left[\begin{array}{c}{y}_{1}\\ {y}_{2}\\ {y}_{3}\end{array}\right]=\left[\begin{array}{c}\left({\displaystyle \prod _{j=1}^{3}{u}_{1j}}\right)\\ \left({\displaystyle \prod _{j=1}^{3}{u}_{2j}}\right)\\ \left({\displaystyle \prod _{j=1}^{3}{u}_{3j}}\right)\end{array}\right]$$
When the Multiply over parameter is set to
Columns
, the block multiplies down the elements of each column
and outputs the resulting 1byN matrix. The block treats
lengthM unoriented vector input as an Mby1
matrix.
$$\begin{array}{ccc}\left[\begin{array}{ccc}{u}_{11}& {u}_{12}& {u}_{13}\\ {u}_{21}& {u}_{22}& {u}_{23}\\ {u}_{31}& {u}_{32}& {u}_{33}\end{array}\right]& & \\ \Downarrow & & \\ \left[\begin{array}{ccc}{y}_{1}& {y}_{2}& {y}_{3}\end{array}\right]& =& \left[\begin{array}{ccc}\left({\displaystyle \prod _{i=1}^{3}{u}_{i1}}\right)& \left({\displaystyle \prod _{i=1}^{3}{u}_{i2}}\right)& \left({\displaystyle \prod _{i=1}^{3}{u}_{i3}}\right)\end{array}\right]\end{array}$$
When the Multiply over parameter is set to Entire
input
, the block multiplies all the elements of the input together and outputs
the resulting scalar.
$$\left[\begin{array}{ccc}{u}_{11}& {u}_{12}& {u}_{13}\\ {u}_{21}& {u}_{22}& {u}_{23}\\ {u}_{31}& {u}_{32}& {u}_{33}\end{array}\right]\Rightarrow y=({\displaystyle \prod _{i=1}^{3}{\displaystyle \prod _{j=1}^{3}{u}_{ij}}})$$
FixedPoint Data Types
The following diagram shows the data types used within the Matrix Product block for fixedpoint signals.
The output of the multiplier is in the product output data type when at least one of the inputs to the multiplier is real. When both of the inputs to the multiplier are complex, the result of the multiplication is in the accumulator data type. For details on the complex multiplication performed, see Multiplication Data Types. You can set the accumulator, product output, intermediate product, and output data types in the block dialog as discussed in Parameters below.
Parameters
Main Tab
 Multiply over
Indicate whether to multiply together the elements of each row, each column, or the entire input.
Data Types Tab
Note
Floatingpoint inheritance takes precedence over the data type settings defined on this pane. When inputs are floating point, the block ignores these settings, and all internal data types are floating point.
 Rounding mode
Specify the rounding mode for fixedpoint operations as one of the following:
Floor
Ceiling
Convergent
Nearest
Round
Simplest
Zero
For more details, see rounding mode.
 Saturate on integer overflow
When you select this parameter, the block saturates the result of its fixedpoint operation. When you clear this parameter, the block wraps the result of its fixedpoint operation. For details on
saturate
andwrap
, see overflow mode for fixedpoint operations. Intermediate product
Specify the intermediate product data type. As shown in FixedPoint Data Types, the output of the multiplier is cast to the intermediate product data type before the next element of the input is multiplied into it. You can set it to:
A rule that inherits a data type, for example,
Inherit: Same as input
An expression that evaluates to a valid data type, for example,
fixdt([],16,0)
Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Product output parameter.
See Specify Data Types Using Data Type Assistant (Simulink) for more information.
 Product output
Specify the product output data type. See FixedPoint Data Types and Multiplication Data Types for illustrations depicting the use of the product output data type in this block. You can set it to:
A rule that inherits a data type, for example,
Inherit: Inherit via internal rule
. For more information on this rule, see Inherit via Internal Rule.A rule that inherits a data type, for example,
Inherit: Same as input
.An expression that evaluates to a valid data type, for example,
fixdt([],16,0)
Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Product output parameter.
See Specify Data Types Using Data Type Assistant (Simulink) for more information.
 Accumulator
Specify the accumulator data type. See FixedPoint Data Types for illustrations depicting the use of the accumulator data type in this block. You can set this parameter to:
A rule that inherits a data type, for example,
Inherit: Inherit via internal rule
. For more information on this rule, see Inherit via Internal Rule.A rule that inherits a data type, for example,
Inherit: Same as input
.A rule that inherits a data type, for example,
Inherit: Same as product output
.An expression that evaluates to a valid data type, for example,
fixdt([],16,0)
Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Accumulator parameter.
See Specify Data Types Using Data Type Assistant (Simulink) for more information.
 Output
Specify the output data type. See FixedPoint Data Types for illustrations depicting the use of the output data type in this block. You can set it to:
A rule that inherits a data type, for example,
Inherit: Same as product output
A rule that inherits a data type, for example,
Inherit: Same as input
.An expression that evaluates to a valid data type, for example,
fixdt([],16,0)
Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Output parameter.
See Control Data Types of Signals (Simulink) for more information.
 Minimum
Specify the minimum value that the block should output. The default value is
[]
(unspecified). Simulink^{®} uses this value to perform:Simulation range checking (see Specify Signal Ranges (Simulink))
Automatic scaling of fixedpoint data types
 Maximum
Specify the maximum value that the block should output. The default value is
[]
(unspecified). Simulink uses this value to perform:Simulation range checking (see Specify Signal Ranges (Simulink))
Automatic scaling of fixedpoint data types
 Lock data type settings against changes by the fixedpoint tools
Select this parameter to prevent the fixedpoint tools from overriding the data types you specify on the block mask.
Supported Data Types
Port  Supported Data Types 

Input 

Output 

Extended Capabilities
Version History
Introduced before R2006a