fspec {bioacoustics} | R Documentation |

## Generate spectrograms

### Description

This function returns the spectrographic representation of a time wave in the absolute scale or in decibels (dB) using the Fast Fourier transform (FFT).

### Usage

```
fspec(
wave,
channel = "left",
FFT_size = 256,
FFT_overlap = 0.875,
FFT_win = "hann",
LPF,
HPF = 0,
tlim = NULL,
flim = NULL,
rotate = FALSE,
to_dB = TRUE
)
```

### Arguments

`wave` |
a Wave object. |

`channel` |
character. Channel to keep for analysis in a stereo recording: "left" or "right". Default setting is left. |

`FFT_size` |
integer. Size of the Fast Fourrier Transform (FFT) window. Default setting is 256. |

`FFT_overlap` |
numeric. Percentage of overlap between two FFT windows (from 0 to 1). Default setting is 0.875. |

`FFT_win` |
character. Specify the type of FFT window: "hann", "blackman4", or "blackman7". Default setting is "hann". |

`LPF` |
integer. Low-Pass Filter (Hz). Frequencies above the cutoff are greatly attenuated. Default setting is the Nyquist frequency of the recording. |

`HPF` |
integer. High-Pass Filter (Hz). Frequencies below the cutoff are greatly attenuated. Default setting is 0 Hz. |

`tlim` |
numeric. Specify the time limits on the X-axis in seconds (s).
Default setting is |

`flim` |
numeric. Specify the frequency limits on the Y-axis in Hz. Default
setting is |

`rotate` |
logical. Should the matrix be rotated 90° counter clockwise ?
Default setting is |

`to_dB` |
logical. Convert magnitude values to decibels (dB)? Default is |

### Value

A matrix of amplitude or decibel (dB) values in the time / frequency domain.

### Examples

```
data(myotis)
image(fspec(myotis, tlim = c(1, 2), rotate = TRUE))
```

*bioacoustics*version 0.2.8 Index]