Filter Design Toolbox

ScaleValues

The ScaleValues property values are specified as a scalar (or vector) that introduces scaling for inputs (and the outputs from cascaded sections in the vector case) during filtering:

• When you only have a single section in your filter:
• Specify the ScaleValues property value as a scalar if you only want to scale the input to your filter.
• Specify the ScaleValues property as a vector of length 2 if you want to specify scaling to the input (scaled with the first entry in the vector) and the output (scaled with the last entry in the vector).
• When you have L cascaded sections in your filter:
• Specify the ScaleValues property value as a scalar if you only want to scale the input to your filter.
• Specify the value for the ScaleValues property as a vector of length L+1 if you want to scale the inputs to every stage in your filter, along with the output:

  The first entry of your vector specifies the input scaling

  Each successive entry specifies the scaling at the output of the next section

  The final entry specifies the scaling for the filter output.

The interpretation of this property is described below with diagrams in Interpreting the ScaleValues Property.

Default value: 1

Remarks: The value of the ScaleValues property is not quantized. Data affected by the presence of a scaling factor in the filter is quantized according to the appropriate data format.

When you apply normalize to a quantized filter, the value for the ScaleValues property is changed accordingly.

It is good practice to choose values for this property that are either positive or negative powers of two.

Interpreting the ScaleValues Property

When you specify the values of the ScaleValues property of a quantized filter, the values are entered as a vector, the length of which is determined by the number of cascaded sections in your filter:

• When you have only one section, the value of the Scalevalues property can be a a scalar or a two-element vector.
• When you have L cascaded sections in your filter, the value of the Scalevalues property can be a scalar or an L+1-element vector.

The following diagram shows how the ScaleValues property values are applied to a quantized filter with only one section.

The following diagram shows how the ScaleValues property values are applied to a quantized filter with two sections.

ReferenceCoefficients

StatesPerSection