Last Modified: March 15, 2017

Computes the single-sided, scaled, cross power spectrum of two real-time signals.

A value that affects the output coefficients when **window type** is Kaiser, Gaussian, or Dolph-Chebyshev.

If **window type** is any other type of window, this node ignores this input.

This input represents the following information for each type of window:

**Kaiser**—Beta parameter**Gaussian**—Standard deviation**Dolph-Chebyshev**—The ratio,*s*, of the main lobe to the side lobe

This input is available only if you wire one of the following data types to **signal x** or **signal y**.

- Waveform
- Waveform in complex double-precision, floating-point numbers
- 1D array of double-precision, floating-point numbers
- 1D array of complex double-precision, floating-point numbers

**Default: **NaN—Causes this node to set beta to 0 for a Kaiser window, the standard deviation to 0.2 for a Gaussian window, and *s* to 60 for a Dolph-Chebyshev window

Time-domain window to apply to the signal.

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

Rectangle | 0 | Applies a rectangle window. |

Hanning | 1 | Applies a Hanning window. |

Hamming | 2 | Applies a Hamming window. |

Blackman-Harris | 3 | Applies a Blackman-Harris window. |

Exact Blackman | 4 | Applies an Exact Blackman window. |

Blackman | 5 | Applies a Blackman window. |

Flat Top | 6 | Applies a Flat Top window. |

4 Term B-Harris | 7 | Applies a 4 Term B-Harris window. |

7 Term B-Harris | 8 | Applies a 7 Term B-Harris window. |

Low Sidelobe | 9 | Applies a Low Sidelobe window. |

Blackman Nutall | 11 | Applies a Blackman Nutall window. |

Triangle | 30 | Applies a Triangle window. |

Bartlett-Hanning | 31 | Applies a Bartlett-Hanning window. |

Bohman | 32 | Applies a Bohman window. |

Parzen | 33 | Applies a Parzen window. |

Welch | 34 | Applies a Welch window. |

Kaiser | 60 | Applies a Kaiser window. |

Dolph-Chebyshev | 61 | Applies a Dolph-Chebyshev window. |

Gaussian | 62 | Applies a Gaussian window. |

Force | 64 | Applies a Force window. |

Exponential | 65 | Applies an Exponential window. |

**Default: **Rectangle

Settings that define how this node returns results.

Length of each set of data. The node performs computation for each set of data.

**sample length** must be greater than zero.

This input is available only if you wire a double-precision, floating-point number to **signal x** or **signal y**.

**Default: **100

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an **error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

**Default: **No error

Sample period of the time-domain signal in seconds.

Set this input to 1/*fs*, where *fs* is the sampling frequency of the time-domain signal.

This input is available only if you wire one of the following data types to **signal x** or **signal y**.

- Double-precision, floating-point number
- 1D array of double-precision, floating-point numbers
- 1D array of complex double-precision, floating-point numbers

**Default: **1

Single-sided cross power spectrum between the input signals *x* and *y*.

Start frequency, in Hz, of the spectrum.

Frequency resolution, in Hz, of the spectrum.

Magnitude of the cross power spectrum.

The phase spectrum, in radians, showing the difference between the phases of the input signals *x* and *y*.

Start frequency, in Hz, of the spectrum.

Frequency resolution, in Hz, of the spectrum.

Phase, in radians, of the cross power spectrum.

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

**error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

If the input signals **signal x** and **signal y** have different lengths, this node first pads the end of the shorter input signal with zeros to make the signals the same length. This node then uses the following equation to compute the two-sided cross power spectrum:

$\frac{\text{FFT}\left(\text{signal x}\right)\times \left(\text{FFT}\right)*\left(\text{signal y}\right)}{{N}^{2}}$

where *N* is the common length of the two input signals after the node pads the end of the shorter input signal with zeros.

To compute the single-sided cross power spectrum, this node converts the two-sided cross power spectrum to the single-sided form.

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: This product does not support FPGA devices