Evaluate polynomial expression

Math Functions / Polynomial Functions

`dsppolyfun`

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 and Math
Function 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]` | $$y={u}^{4}+2{u}^{3}+3{u}^{2}+4u+5$$ |

`[1 0 3 0 5]` | $$y={u}^{4}+3{u}^{2}+5$$ |

`[1 2+i 3 4-3i 5i]` | $$y={u}^{4}+\left(2+i\right){u}^{3}+3{u}^{2}+\left(4-3i\right)u+5i$$ |

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.

**Use constant coefficients**Select to enable the

**Constant coefficients**parameter and disable the`Coeffs`

input 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.

Double-precision floating point

Single-precision floating point

Least Squares Polynomial Fit | DSP System Toolbox |

Math Function | Simulink |

Sum | Simulink |

`polyval` | MATLAB |

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