Polynomial Evaluation
Evaluate polynomial expression
Library
Math Functions / Polynomial Functions
dsppolyfun
Description
The Polynomial Evaluation block applies a polynomial function to the real or complex
input at the In port.
y = polyval(u) % Equivalent MATLAB code
The Polynomial Evaluation block performs these types of operation more efficiently than the equivalent construction using Simulink® Sum (Simulink) and Math Function (Simulink) blocks.
When you select the Use constant coefficients check box, you
specify the polynomial expression in the Constant coefficients
parameter. When you do not select Use constant coefficients, a
variable polynomial expression is specified by the input to the
Coeffs port. In both cases, the polynomial is specified as a
vector of real or complex coefficients in order of descending exponents.
The table below shows some examples of the block's operation for various coefficient vectors.
| Coefficient Vector | Equivalent Polynomial Expression |
|---|---|
[1 2 3 4 5] | |
[1 0 3 0 5] | |
[1 2+i 3 4-3i 5i] |
Each element of a vector or matrix input to the In port is
processed independently, and the output size is the same as the input.
Parameters
- Use constant coefficients
Select to enable the Constant coefficients parameter and disable the
Coeffsinput port.- Constant coefficients
Specify the vector of polynomial coefficients to apply to the input, in order of descending exponents. This parameter is enabled when you select the Use constant coefficients check box.
Supported Data Types
Double-precision floating point
Single-precision floating point
See Also
| Least Squares Polynomial Fit | DSP System Toolbox |
| Math Function (Simulink) | Simulink |
| Sum (Simulink) | Simulink |
polyval | MATLAB |