Version:

Last Modified: January 9, 2017

Filters an input sequence using a specific filter. You specify the initial conditions for this node.

Input signal to filter.

This input can be an array of double-precision floating-point numbers or an array of complex double-precision floating-point numbers.

The input filter.

Structure of the filter.

Name | Value | Description |
---|---|---|

IIR Cascade 2nd Order | 0 | Uses IIR second-order filter stages. |

IIR Cascade 4th Order | 1 | Uses IIR fourth-order filter stages. |

IIR Direct | 2 | Uses the direct-form IIR filter. |

FIR | 3 | Uses the FIR filter. |

**Default: **IIR Cascade 2nd Order

Forward coefficients of the filter.

**Default: **0

Reverse coefficients of the filter.

**Default: **0

The sampling frequency in Hz.

This value must be greater than zero.

**Default: **0

The initial internal filter state. This input must be passed from the **final conditions** output of the previous call to this node to filter samples continuously.

Values of the initial internal filter state.

Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

**Default: **No error

The filtered signal.

The final internal filter state. You can pass this output to the **initial conditions** input of the next call to this node to filter samples continuously.

Values of the final internal filter state.

If **filter structure** is FIR, this node obtains the elements of **filtered signal** using the following equation:

${y}_{i}=\begin{array}{cc}\underset{j=0}{\overset{{N}_{b}-1}{\sum}}{b}_{j}{x}_{i-j}& \mathrm{for}(i\ge 0)\end{array}$

where

*y*is**filtered signal***N*_{b}is the number of FIR coefficients*b*_{j}is the filter coefficients

If **filter structure** is IIR Direct, this node obtains the elements of **filtered signal** using the following equation:

${y}_{i}=\begin{array}{cc}\frac{1}{{a}_{0}}\left(\underset{j=0}{\overset{{N}_{b}-1}{\sum}}{b}_{j}{x}_{i-j}-\underset{k=1}{\overset{{N}_{a}-1}{\sum}}{a}_{k}{y}_{i-k}\right)& \mathrm{for}(i\ge 0)\end{array}$

where

*y*is**filtered signal***N*_{b}is the number of**forward coefficients***b*_{j}is the**forward coefficients***N*_{a}is the number of**reverse coefficients***a*_{k}is the**reverse coefficients**

If **filter structure** is IIR Cascade 2nd Order or IIR Cascade 4th Order, this node obtains the elements of **filtered signal** with a cascade of second- or fourth-order filter stages. The output of one filter stage is the input to the next filter stage for all *N*_{s} filter stages.

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported