EXTRACT

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Contents

• Description
• Parameters
• Default properties
• Interfacing function
• Computational function
• Example
• See also

Description

The EXTRACT block extracts some elements from the input matrix. The size of the output depends on the number of rows and number of columns to extract.

The elements of the parameters Lines to extract and Columns to extract specify respectively the indexes of the lines and the columns to be extracted.

The writing of these parameters obeys to the rules of extraction (see extraction), in particular you can give a range of indexes with the colon operator (:).

Parameters

• Datatype (1=real double 2=Complex)

  It indicates the type of the output. It support only the two types double (1) and complex (2). If we input another entry in this label xcos will print the message "Datatype is not supported".

  Properties : Type 'vec' of size 1.

• Lines to extract

  A vector indicating the indexes of lines to be extracted.

  Properties : Type 'mat' of size [1,-1].

• Columns to extract

  A vector indicating the indexes of columns to be extracted..

  Properties : Type 'mat' of size [1,-1].

Default properties

• always active: no

• direct-feedthrough: yes

• zero-crossing: no

• mode: no

• regular inputs:

  - port 1 : size [-1,-2] / type 1

• regular outputs:

  - port 1 : size [1,1] / type 1

• number/sizes of activation inputs: 0

• number/sizes of activation outputs: 0

• continuous-time state: no

• discrete-time state: no

• object discrete-time state: no

• name of computational function: extract

Example

A = [1 2 3;4 5 6;7 8 9]
If the "Lines to extract" is [1 2] and the "Column to extract" is [1 3] then the output is
B = [1 3 ; 4 6]

Interfacing function

• SCI/modules/scicos_blocks/macros/MatrixOp/EXTRACT.sci

Computational function

• SCI/modules/scicos_blocks/src/c/extract.c

• SCI/modules/scicos_blocks/src/c/extractz.c

See also

• EXTTRI — Triangular or Diagonal Extraction