User`s guide
Multiport Selector
5-322
5Multiport Selector
Purpose Distribute arbitrary subsets of input rows or columns to multiple output ports.
Library Signal Management / Indexing
Description The Multi-port Selector block extracts multiple subsets of rows or columns 
from M-by-N input matrix u, and propagates each new submatrix to a distinct 
output port. A length-M 1-D vector input is treated as an M-by-1 matrix.
The Indices to output parameter is a cell array whose kth cell contains a 
one-dimensional indexing expression specifying the subset of input rows or 
columns to be propagated to the kth output port. The total number of cells in 
the array determines the number of output ports on the block. 
When the 
Select parameter is set to Rows, the specified one-dimensional 
indices are used to select matrix rows, and all elements on the chosen rows are 
included. When the 
Select parameter is set to Columns, the specified 
one-dimensional indices are used to select matrix columns, and all elements on 
the chosen columns are included. A given input row or column can appear any 
number of times in any of the outputs, or not at all.
The 
Indices to output parameter is tunable, so you can change the values of 
the indices at any time during the simulation; however, the number of cells in 
the array (i.e., the number of output ports) and the size of each submatrix in 
the output must remain the same while the simulation is running. 
When an index references a nonexistent row or column of the input, the block 
reacts with the behavior specified by the 
Invalid index parameter. The 
following options are available:
•
Clip index – Clip the index to the nearest valid value, and do not issue an 
alert. 
Example: For a 64-by-4 input with 
Select = Rows, an index of 72 is clipped 
to 64; with 
Select = Columns, an index of 72 is clipped to 4. In both cases, an 
index of -2 is clipped to 1.
•
Clip and warn – Display a warning message in the MATLAB command 
window, and clip as above.
•
Generate error – Display an error dialog box and terminate the simulation.










