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Selector

Select input elements from vector, matrix, or multidimensional signal

  • Library:
  • Simulink / Signal Routing

Description

The Selector block generates as output selected or reordered elements of an input vector, matrix, or multidimensional signal.

Based on the value you enter for the Number of input dimensions parameter, a table of indexing settings is displayed. Each row of the table corresponds to one of the input dimensions in Number of input dimensions. For each dimension, you define the elements of the signal to work with. Specify a vector signal as a 1-D signal and a matrix signal as a 2-D signal. When you configure the Selector block for multidimensional signal operations, the block icon changes.

For example, assume a 6-D signal with a one-based index mode. The table of the Selector block dialog changes to include one row for each dimension. If you define dimensions with these entries:

RowIndex OptionIndexOutput Size
1Select all  
2Starting index (dialog)25
3Index vector (dialog)[1 3 5] 
4Starting index (port) 8
5Index vector (port)  
6Starting and ending indices (port)  

The output will be Y=U(1:end,2:6,[1 3 5],Idx4:Idx4+7,Idx5, Idx6(1):Idx6(2)), where Idx4, Idx5, and Idx6 are the index ports for dimensions 4, 5, and 6.

You can use an array of buses as an input signal to a Selector block. For details about defining and using an array of buses, see Combine Buses into an Array of Buses.

Ports

Input

expand all

Input signal and source of elements to output signal.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean | fixed point | enumerated | bus

External port specifying an index for the selection of the corresponding output element.

Dependencies

To enable an external index port, in the corresponding row of the Index Option table, set Index Option to Index vector (port), Starting index (port), or Starting and ending indices (port).

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | fixed point | enumerated

Output

expand all

Output signal generated from selected or reordered elements of input signal.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean | fixed point | enumerated | bus

Parameters

expand all

Specifies the number of dimensions of the output signal.

Command-Line Information

Parameter: NumberOfDimensions
Type: character vector
Values: integer
Default: '1'

Specifies the indexing mode. If One-based is selected, an index of 1 specifies the first element of the input vector. If Zero-based is selected, an index of 0 specifies the first element of the input vector.

Defines, by dimension, how the elements of the signal are to be indexed. From the list, select:

  • Select all

    No further configuration is required. All elements are selected.

  • Index vector (dialog)

    Enables the Index column. Enter the vector of indices of the elements.

  • Index vector (port)

    No further configuration is required.

  • Starting index (dialog)

    Enables the Index and Output Size columns. Enter the starting index of the range of elements to select in the Index column and the number of elements to select in the Output Size column.

  • Starting index (port)

    Enables the Output Size column. Enter the number of elements to be selected in the Output Size column.

  • Starting and ending indices (port)

    No further configuration is required.

    Using this option results in a variable-size output signal. When you update, the output dimension is set to be the same as the input signal dimension. During execution, the output dimension is updated based on the signal feeding the index.

    When logging output signal data, signals not selected are padded with NaN values.

The Index and Output Size columns appear as needed.

Command-Line Information

Parameter: IndexOptionArray
Type: character vector
Values: 'Select all' | 'Index vector (dialog)' | 'Index option (port)' | 'Starting index (dialog)' | 'Starting index (port)' | Starting and ending indices (port)
Default: 'Index vector (dialog)'

If the Index Option is Index vector (dialog), enter the index of each element you are interested in.

If the Index Option is Starting index (dialog), enter the starting index of the range of elements to be selected.

Command-Line Information

Parameter: IndexParamArray
Type: character vector
Values: cell array
Default: '{ }'

Specifies the width of the block output signal.

Command-Line Information

Parameter: OutputSizeArray
Type: character vector
Values: cell array
Default: '{ }'

Specify the width of the block input signal for 1-D signals. Enter -1 to inherit from the driving block.

Command-Line Information

Parameter: InputPortWidth
Type: character vector
Values: integer
Default: '1'

Specify the sample time as a value other than -1. For more information, see Specify Sample Time.

Dependencies

This parameter is not visible unless it is explicitly set to a value other than -1. To learn more, see Blocks for Which Sample Time Is Not Recommended.

Programmatic Use

Block Parameter: SampleTime
Type: character vector
Values: scalar
Default: '-1'

Block Characteristics

Data Types

double | single | Boolean | base integer | fixed point | enumerated

Multidimensional Signals

Yes

Variable-Size Signals

Yes

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion
Convert floating-point algorithms to fixed point using Fixed-Point Designer™.

Introduced before R2006a

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