FixPt Matrix Gain (Fixed-Point Blockset)

The FixPt Matrix Gain block is a masked S-function that multiplies the input by a constant matrix (referred to as the matrix gain). The block generates its output by multiplying the input by a specified matrix

where K is the matrix gain and u is the input. If the matrix has m rows and n columns, then the input to this block should be a vector of length n. The output is a vector of length m.

The gain is specified with the Gain matrix value parameter.

The Parameter data type parameter can have the same values as the Output data type parameter as discussed in "Block Parameters". Additionally, if Parameter data type is a generalized fixed-point number, then you can select from these scaling modes:

Use Specified Scaling --This is the default mode; it uses the scaling from the Parameter scaling parameter.
Use Best Precision: Element-wise -- This mode produces radix points such that the precision is maximized for each element of the Gain matrix value matrix.
Use Best Precision: Row-wise -- This mode produces a common radix point for each element of a Gain matrix value row based on the best precision for the largest value of that row.
Use Best Precision: Column-wise -- This mode produces a common radix point for each element of a Gain matrix value column based on the best precision for the largest value of that column.
Use Best Precision: Matrix-wise -- This mode produces a common radix point for each element of the Gain matrix value matrix based on the best precision for the largest value of the matrix.

For a description of all other parameters, refer to "Block Parameters".

The block icon always displays a K. For a description of how the block icon displays the output data type, refer to "Block Icon Display".

Parameters and Dialog Box

Gain matrix value: Specify as a scalar or vector.
Parameter data type: Any data type supported by the Fixed-Point Blockset.
Parameter scaling: Radix point-only or slope/bias scaling. Additionally, the gain can be scaled using the constant matrix scaling modes for maximizing precision. These scaling modes are only available for generalized fixed-point data types.
Output data type: Any data type supported by the Fixed-Point Blockset.
Output scaling: Radix point-only or slope/bias scaling. These scaling modes are only available for generalized fixed-point data types.
Lock output scaling: If checked, Output scaling is locked.This feature is only available for generalized fixed-point output.
Round toward: Rounding mode for the fixed-point output.
Saturate to max or min when overflows occur: If checked, fixed-point overflows saturate. Otherwise, they wrap.
Override with doubles: If checked, the Output data type is overridden with doubles.
Log minimums and maximums: If checked, minimum and maximum simulation values are logged to the workspace.

Conversions and Operations

The Gain matrix value parameter is converted from doubles to the specified data type offline using round-to-nearest and saturation. Refer to "Parameter Conversions" in the manual for more information about parameter conversions.

The FixPt Matrix Gain block first multiples its inputs by the Gain matrix value parameter, converts those results to the output data type using the specified rounding and overflow modes, and then performs the summation. Refer to "Rules for Arithmetic Operations" in the manual for more information about the rules this block adheres to when performing operations.

Characteristics


Input Ports	Any data type supported by the blockset
Output Port	Any data type supported by the blockset
Direct Feedthrough	Yes
Sample Time	Inherited
Scalar Expansion	No
States	0
Vectorized	Yes

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