Description Usage Arguments Details Author(s) References See Also

View source: R/GPPFouriertest.R

GPPFourier test function

1 2 3 4 5 |

`x` |
O2 time series from which GPP is to be calculated |

`dt` |
Sample time step |

`units` |
Time unit of sampling time step |

`Detrend` |
Toggle time series detrending. See GPPFourierPreprocess |

`filter` |
Toggle time series filtering. See GPPFourierPreprocess |

`Nfilt` |
Moving average filter width |

`circular` |
Moving average circular boundary condition (see documentation of filter()) |

`sides` |
Moving average central or one sided (see documentation of filter()) |

`filtcorrect` |
Logical controlling whether GPP estimate is corrected for signal falsely removed by filtering |

`trunclight` |
Use truncated sinusoid approximation for light&GPP. If FALSE, a sinusoid approximation is assumed |

`fDL` |
Relative fraction of light hours during the day |

`usefft` |
If FALSE the amplitude at diel freqyency is computed directly. If TRUE fft() is used to estimate amplitude at diel frequency. |

`padlength` |
Number of zeroes to be appended to the time series to increase frequency resolution |

`fourierderive` |
Calculate derivative in the frequency domain or not |

`confine` |
Confine time series to integer number of days or tidal cycles |

`taper` |
Taper the time series with spec.taper() |

`p` |
Fraction of the time series to be tapered at each side |

This function allows to play around with the basics behind GPPFourier and GPPFourierPreprocess

`trunclight`

controls whether GPP is assumed to evolving as a truncated
sinusoid over a day or as a pure sinusoidal. This assumption determines the
relation between time averaged GPP and the Fourier amplitude at diel
frequency

`usefft`

: by default `GPPFourier()`

calculates the amplitude at
diel frequency directly `fft()`

calculates the full Fourier transform
of the time series. The amplitude at diel frequency can be derived from the
Fourier transform

`fourierderive`

: if TRUE time derivation is performed in the Fourier
domain by multiplying with i x omega, omega being the diurnal angular
frequency. Thus the GPPFouriertest returns the amplitude at diel frequency of dx/dt. If
fourierderive is FALSE, the amplitude at diel frequency of x is returned
(multiplied with the factor determined by `trunclight`

Tom Cox <tom.cox@uantwerp.be>

Cox T.J.S. et al. (2015) 'Estimating primary production from oxygen time series: a novel approach in the frequency domain', Limnology And Oceanography:Methods 13, 529-552. DOI: 10.1002/lom3.10046

GPPFourier, GPPFourierPreprocess

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.