Overwrite submatrix or subdiagonal of input
Math Functions / Matrices and Linear Algebra / Matrix Operations
dspmtrx3
Signal Management / Indexing
dspindex
The Overwrite Values block overwrites a contiguous submatrix or subdiagonal of an input matrix. You can provide the overwriting values by typing them in a block parameter, or through an additional input port, which is useful for providing overwriting values that change at each time step.
The block accepts scalars, vectors and matrices. The output always has the same size as the original input signal, not necessarily the same size as the signal containing the overwriting values. The input(s) and output of this block must have the same data type.
The Source of overwriting value(s) parameter determines how you must provide the overwriting values, and has the following settings.
Specify via dialog
— You must provide the overwriting
value(s) in the Overwrite with parameter. The block uses the same
overwriting values to overwrite the specified portion of the input at each time step. To learn
how to specify valid overwriting values, see Valid Overwriting Values.
Second input port
— You must provide overwriting values
through a second block input port, V
. Use this setting to provide different
overwriting values at each time step. The output inherits its size and rate from the input
signal, not the overwriting values.
The rate at which you provide the overwriting values through input port
V
must match the rate at which the block receives each input matrix at
input port A
. In other words, the input signals must have the same
Simulink^{®} sample time.
The overwriting values can be a single constant, vector, or matrix, depending on the portion of the input you are overwriting, regardless of whether you provide the overwriting values through an input port or by providing them in the Overwrite with parameter.
Valid Overwriting Values
Portion of Input to Overwrite  Valid Overwriting Values  Example 

A single element in the input  Any constant value, v  v 
A lengthk portion of the diagonal  Any lengthk column or row vector, v  $$k=3\text{}v=\left[\begin{array}{ccc}2& 4& 6\end{array}\right]\text{or}\left[\begin{array}{c}2\\ 4\\ 6\end{array}\right]$$ 
A lengthk portion of a row  Any lengthk row vector, v  $$k=3\text{}v=\left[\begin{array}{ccc}2& 4& 6\end{array}\right]$$ 
A lengthk portion of a column
 Any lengthk column vector, v  $$k=2\text{}v=\left[\begin{array}{c}4\\ 6\end{array}\right]$$ 
An mbyn submatrix  Any mbyn matrix, v  $$\begin{array}{c}m=2\\ n=3\end{array}\text{}v=\left[\begin{array}{lll}4\hfill & 5\hfill & 6\hfill \\ 7\hfill & 8\hfill & 9\hfill \end{array}\right]$$ 
This block supports Simulink virtual buses.
Note
Only some of the following parameters are visible in the dialog box at any one time.
Determines whether to overwrite a specified submatrix or a specified portion of the diagonal.
Determines where you must provide the overwriting values: either through an input port, or by providing them in the Overwrite with parameter. For more information, see Specifying the Overwriting Values.
The value(s) with which to overwrite the specified portion of the input matrix. Enabled
only when Source of overwriting value(s) is set to Specify
via dialog
. To learn how to specify valid overwriting values, see Valid Overwriting Values.
The range of input rows to be overwritten. Options are All
rows
, One row
, or Range of
rows
. For descriptions of these options, see Parameters.
The input row that is the first row of the submatrix that the block overwrites. For a
description of the options for the Row and Starting
row parameters, see Settings for Row, Column, Starting Row, and Starting Column Parameters.
Row is enabled when Row span is set to
One row
, and Starting row when Row
span is set to Range of rows
.
Index of the input row that is the first row of the submatrix that the block overwrites.
See how to use these parameters in Settings for Row, Column, Starting Row, and Starting Column Parameters.
Row index is enabled when Row is set to
Index
, and Starting row index when
Starting row is set to Index
.
The offset of the input row that is the first row of the submatrix that the block
overwrites. See how to use these parameters in Settings for Row, Column, Starting Row, and Starting Column Parameters.
Row offset is enabled when Row is set to
Offset from middle
or Offset from last
,
and Starting row offset is enabled when Starting row
is set to Offset from middle
or Offset from
last
.
The input row that is the last row of the submatrix that the block overwrites. For a
description of this parameter's options, see Settings for Ending Row and Ending Column Parameters. This parameter is enabled when
Row span is set to Range of rows
, and
Starting row is set to any option but
Last
.
Index of the input row that is the last row of the submatrix that the block overwrites.
See how to use this parameter in Settings for Ending Row and Ending Column Parameters.
Enabled when Ending row is set to
Index
.
The offset of the input row that is the last row of the submatrix that the block
overwrites. See how to use this parameter in Settings for Ending Row and Ending Column Parameters. Enabled when Ending
row is set to Offset from middle
or Offset
from last
.
The range of input columns to be overwritten. Options are All
columns
, One column
, or Range of
columns
. For descriptions of the analogous row options, see Parameters.
The input column that is the first column of the submatrix that the block overwrites. For
a description of the options for the Column and Starting
column parameters, see Settings for Row, Column, Starting Row, and Starting Column Parameters.
Column is enabled when Column span is set to
One column
, and Starting column
when Column span is set to Range of
columns
.
Index of the input column that is the first column of the submatrix that the block
overwrites. See how to use these parameters in Settings for Row, Column, Starting Row, and Starting Column Parameters.
Column index is enabled when Column is set to
Index
, and Starting column index
when Starting column is set to
Index
.
The offset of the input column that is the first column of the submatrix that the block
overwrites. See how to use these parameters in Settings for Row, Column, Starting Row, and Starting Column Parameters.
Column offset is enabled when Column is set to
Offset from middle
or Offset from last
,
and Starting column offset is
enabled when Starting column is set to Offset from
middle
or Offset from last
.
The input column that is the last column of the submatrix that the block overwrites. For
a description of this parameter's options, see Settings for Ending Row and Ending Column Parameters. This parameter is enabled when
Column span is set to Range of columns
, and
Starting column is set to any option but
Last
.
Index of the input column that is the last column of the submatrix that the block
overwrites. See how to use this parameter in Settings for Ending Row and Ending Column Parameters. This parameter is enabled when
Ending column is set to Index
.
The offset of the input column that is the last column of the submatrix that the block
overwrites. See how to use this parameter in Settings for Ending Row and Ending Column Parameters. This parameter is enabled when
Ending column is set to Offset from middle
or
Offset from last
.
The range of diagonal elements to be overwritten. Options are All
elements
, One element
, or Range of
elements
. For descriptions of these options, see Overwriting a Subdiagonal.
The input diagonal element that is the first element in the subdiagonal that the block
overwrites. For a description of the options for the Element and
Starting element parameters, see Element and Starting Element Parameters. Element is enabled
when Element span is set to One element
, and
Starting element when Element span is set to
Range of elements
.
Index of the input diagonal element that is the first element of the subdiagonal that the
block overwrites. See how to use these parameters in Element and Starting Element Parameters. Element index is
enabled when Element is set to Index
, and
Starting element index when Starting element is set
to Index
.
The offset of the input diagonal element that is the first element of the subdiagonal
that the block overwrites. See how to use these parameters in Element and Starting Element Parameters. Element
offset is enabled when Element is set to Offset
from middle
or Offset from last
, and
Starting element offset is
enabled when Starting element is set to Offset from
middle
or Offset from last
.
The input diagonal element that is the last element of the subdiagonal that the block
overwrites. For a description of this parameter's options, see Ending Element Parameters. This parameter is enabled when Element
span is set to Range of elements
, and
Starting element is set to any option but
Last
.
Index of the input diagonal element that is the last element of the subdiagonal that the
block overwrites. See how to use this parameter in Ending Element Parameters. This parameter is enabled when Ending element
is set to Index
.
The offset of the input diagonal element that is the last element of the subdiagonal that
the block overwrites. See how to use this parameter in Ending Element Parameters. This parameter is enabled when Ending
element is set to Offset from
middle
or Offset from last
.
To overwrite a submatrix, follow these steps:
Set the Overwrite parameter to
Submatrix
.
Specify the overwriting values as described in Specifying the Overwriting Values.
Specify which rows and columns of the input matrix are contained in the submatrix that you want to overwrite by setting the Row span parameter to one of the following options and the Column span to the analogous columnrelated options:
All rows
— The submatrix contains all rows of the
input matrix.
One row
— The submatrix contains only one row of the
input matrix, which you must specify in the Row parameter, as described
in the following table.
Range of rows
— The submatrix contains one or more
rows of the input, which you must specify in the Starting Row and
Ending row parameters, as described in the following tables.
When you set Row span to One
row
or Range of rows
, you need to further specify
the row(s) contained in the submatrix by setting the Row or
Starting row and Ending row parameters. Likewise,
when you set Column span to One column
or
Range of columns
, you must further specify the column(s) contained
in the submatrix by setting the Column or Starting
column and Ending column parameters. For descriptions of the
settings for these parameters, see the following tables.
Settings for Row, Column, Starting Row, and Starting Column Parameters
Settings for Specifying the Submatrix's First Row or Column  First Row of Submatrix (Only row for Row span = One row)  First Column of Submatrix (Only row for Row span = One row) 

 First row of the input  First column of the input 
 Input row specified in the Row index parameter  Input column specified in the Column index parameter 
 Input row with the index  Input column with the index 
 Last row of the input  Last column of the input 
 Input row with the index  Input column with the index 
 Input row with the index  Input columns with the index 
Settings for Ending Row and Ending Column Parameters
Settings for Specifying the Submatrix's Last Row or Column  Last Row of Submatrix  Last Column of Submatrix 

 Input row specified in the Ending row index parameter  Input column specified in the Ending column index parameter 
 Input row with the index  Input column with the index 
 Last row of the input  Last column of the input 
 Input row with the index  Input column with the index 
 Input row with the index  Input columns with the index 
For example, to overwrite the lowerright 2by3 submatrix of a 3by5 input matrix with all zeros, enter the following set of parameters:
Overwrite = Submatrix
Source of overwriting value(s) = Specify via
dialog
Overwrite with = 0
Row span = Range of rows
Starting row = Index
Starting row index = 2
Ending row = Last
Column span = Range of columns
Starting column = Offset from last
Starting column offset = 2
Ending column = Last
The following figure shows the block with the above settings overwriting a portion of a 3by5 input matrix.
There are often several possible parameter combinations that select the
same submatrix from the input. For example, instead of specifying
Last
for Ending column, you could select the
same submatrix by specifying
Ending column = Index
Ending column index = 5
To overwrite a subdiagonal, follow these steps:
Set the Overwrite parameter to
Diagonal
.
Specify the overwriting values as described in Specifying the Overwriting Values.
Specify the subdiagonal that you want to overwrite by setting the Diagonal span parameter to one of the following options:
All elements
— Overwrite the entire input
diagonal.
One element
— Overwrite one element in the diagonal,
which you must specify in the Element parameter (described
below).
Range of elements
— Overwrite a portion of the input
diagonal, which you must specify in the Starting element and
Ending element parameters, as described in the following table.
When you set Diagonal span to One
element
or Range of elements
, you need to further
specify which diagonal element(s) to overwrite by setting the Element or
Starting element and Ending element parameters. See
the following tables.
Element and Starting Element Parameters
Settings for Element and Starting Element Parameters  First Element in Subdiagonal (Only element when Diagonal span = One element) 

 Diagonal element in first row of the input 
 kth diagonal element, where k is the value of the Element index or Starting element index parameter 
 Diagonal element in the row with the index

 Diagonal element in the last row of the input 
 Diagonal element in the input row with the index

 Diagonal element in the input row with the index

Ending Element Parameters
Settings for Ending Element Parameter  Last Element in Subdiagonal 

 kth diagonal element, where k is the value of the Ending element index parameter 
 Diagonal element in the row with the index

 Diagonal element in the last row of the input 
 Diagonal element in the input row with the index

 Diagonal element in the input row with the index

The input(s) and output of this block must have the same data type.
Port  Supported Data Types 

A 

V 

B 

Reshape (Simulink)  Simulink 
Selector (Simulink)  Simulink 
Submatrix  DSP System Toolbox 
Variable Selector  DSP System Toolbox 
reshape  MATLAB 