mtmPL {astrochron} | R Documentation |

## Multitaper Method Spectral Analysis with Power Law (1/f) fit

### Description

Multitaper Method (MTM) Spectral Analysis with Power Law (1/f) fit

### Usage

```
mtmPL(dat,tbw=3,ntap=NULL,padfac=5,demean=T,detrend=F,siglevel=0.9,flow=NULL,fhigh=NULL,
output=0,CLpwr=T,xmin=0,xmax=Nyq,pl=1,sigID=F,genplot=T,verbose=T)
```

### Arguments

`dat` |
Stratigraphic series for MTM spectral analysis. First column should be location (e.g., depth), second column should be data value. |

`tbw` |
MTM time-bandwidth product. |

`ntap` |
Number of DPSS tapers to use. By default, this is set to (2*tbw)-1. |

`padfac` |
Pad with zeros to (padfac*npts) points, where npts is the original number of data points. |

`demean` |
Remove mean from data series? (T or F) |

`detrend` |
Remove linear trend from data series? (T or F) |

`siglevel` |
Significance level for peak identification. |

`flow` |
Lowest frequency to include in 1/f fit |

`fhigh` |
Highest frequency to include in 1/f fit |

`output` |
What should be returned as a data frame? (0=nothing; 1=spectrum + CLs + power law fit; 2=sig peak freqs; 3=sig peak freqs + prob; 4=all) |

`CLpwr` |
Plot power law noise confidence levels on power spectrum (in addition to the power law fit)? (T or F) |

`xmin` |
Smallest frequency for plotting. |

`xmax` |
Largest frequency for plotting. |

`pl` |
Power spectrum plotting: (1) linear frequency-log spectral power, (2) linear frequency-linear spectral power (3) log frequency-log spectral power, (4) log frequency-linear spectral power |

`sigID` |
Identify signficant frequencies on power and probabilty plots? (T or F) |

`genplot` |
Generate summary plots? (T or F) |

`verbose` |
Verbose output? (T or F) |

### Details

Candidiate astronomical cycles are identified via isolation of those frequencies that achieve the required (e.g., 90 percent) power law confidence level and MTM harmonic F-test confidence level. Allowance is made for the smoothing inherent in the MTM power spectral estimate as compared to the MTM harmonic spectrum. That is, an F-test peak is reported if it achieves the required MTM harmonic confidence level, while also achieving the required power law confidence level within +/- half the power spectrum bandwidth resolution. One additional criterion is included to further reduce the false positive rate, a requirement that significant F-tests must occur on a local power spectrum high, which is parameterized as occurring above the local red noise background estimate. See Meyers (2012) for futher information.

### References

S.R. Meyers, 2012,
*Seeing Red in Cyclic Stratigraphy: Spectral Noise Estimation for Astrochronology*: Paleoceanography, 27, PA3228, doi:10.1029/2012PA002307.

Rahim, K.J. and Burr W.S. and Thomson, D.J., 2014,
*Appendix A: Multitaper R package in "Applications of Multitaper Spectral Analysis to Nonstationary Data"*, PhD diss., Queen's Univieristy, pp 149-183. http://hdl.handle.net/1974/12584

Thomson, D. J., 1982,
*Spectrum estimation and harmonic analysis*, Proc. IEEE, 70, 1055-1096, doi:10.1109/PROC.1982.12433.

### See Also

`eha`

, `lowspec`

, `mtm`

, `mtmAR`

, `mtmML96`

, `periodogram`

, and `spec.mtm`

*astrochron*version 1.3 Index]