Learn R Programming

⚠️There's a newer version (1.5) of this package.Take me there.

astrochron (version 1.1)

A Computational Tool for Astrochronology

Description

Routines for astrochronologic testing, astronomical time scale construction, and time series analysis . Also included are a range of statistical analysis and modeling routines that are relevant to time scale development and paleoclimate analysis.

Copy Link

Version

Install

install.packages('astrochron')

Monthly Downloads

799

Version

1.1

License

GPL-3

Maintainer

Stephen Meyers

Last Published

October 5th, 2021

Functions in astrochron (1.1)

Generate AR(1) surrogates

AR(1) + ETP simulation routine

Average Spectral Misfit

astrochron-package

astrochron: A Computational Tool for Astrochronology

Automatically plot multiple stratigraphic series, with smoothing if desired

Arcsine transformation of stratigraphic series

Generate autoregressive moving-average model

Bandpass filter stratigraphic series

Anchor a floating astrochronology to a radioisotopic age

Obliquity and precession periods of Berger et al. (1992)

Adjust spectrum confidence levels for multiple comparisons

Calculate eccentricity and precession periods in ka, given g and k in arcsec/yr

Bioturbate time series using diffusion model from Guinasso and Schinck (1975), as in Liu et al. (2021)

constantSedrate

Apply a constant sedimentation rate model to transform a spatial series to temporal series

Model differential accumulation

Subtract linear trend from stratigraphic series

Apply cosine taper to stratigraphic series

Convolution through Fast Fourier Transform

Evolutive Harmonic Analysis & Evolutive Power Spectral Analysis

Generate eccentricity-tilt-precession models

Generate harmonic model

eTimeOpt: Evolutive implementation of TimeOpt (Meyers, 2015; Meyers, 2019)

Create non-linear response by clipping stratigraphic series

Remove mean value from stratigraphic series

Interactively delete points in plot

Combine multiple vectors

Track eTimeOpt r2 maxima

Apply Hann taper to stratigraphic series

Imbrie and Imbrie (1980) ice sheet model

Download Laskar et al. (2004, 2011a, 2011b) astronomical solutions

Interactively identify points in plot

Extract record from EHA time-frequency output or eAsm output

Flip stratigraphic series

Wiener Deconvolution through Fast Fourier Transform

Divide by linear trend in stratigraphic series

Evolutive Average Spectral Misfit

Apply DPSS taper to stratigraphic series

Log transformation of stratigraphic series

Piecewise linear interpolation of stratigraphic series

Tune stratigraphic series to an astronomical target using graphical interface

Calculate moving window correlation coefficient for two stratigraphic series, using a 'dynamic window'

Apply Gaussian taper to stratigraphic series

Adjust spectral p-values for multiple comparisons

Isolate data from a specified stratigraphic interval

Convert record of local spatial frequency (from EHA) to sedimentation rate curve

List column numbers for each variable

Hilbert transform of stratigraphic series

Track ASM null hypothesis significance level minima in eASM results

Download file from astrochron data server

Query R for color information

impulseResponse

Impulse response function calculation

Fit and remove Lowess smoother from stratigraphic series

Pad stratigraphic series with zeros

Lowpass filter stratigraphic series

Mann and Lees (1996) robust red noise MTM analysis

Determine the total power within a given bandwidth

Replace values < 0 with 0

Determine 'dynamic moving window' for stratigraphic series, adjusting for changing sample density to maintain a window of constant duration; output on evenly spaced grid

Robust Locally-Weighted Regression Spectral Background Estimation

Replace values <= 0 with smallest positive value

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

Multitaper method spectral analysis

TimeOptPlot: Generate summary figure for TimeOpt analyses

Apply 'ramping' sedimentation rate model to convert time to stratigraphy

Standardize variable in stratigraphic series

Create lithofacies rank series from bed thickness data

Determine 'dynamic moving window' for stratigraphic series, adjusting for changing sample density to maintain a window of constant duration

Remove Gaussian kernel smoother from stratigraphic series

'Dynamic window' moving average, median and variance of stratigraphic series, using evenly spaced spatial/temporal grid

Estimate power law (1/f) fit to power spectrum

TimeOptMCMC: Evaluation of eccentricity-related amplitude modulation and bundling in paleoclimate data ("TimeOpt"), with uncertainties via Markov-Chain Monte Carlo

TimeOpt: Evaluation of eccentricity-related amplitude modulation and bundling in paleoclimate data

Identify maxima of peaks in series, filter at desired threshold value

Intermediate spectrum test of Thomson et al. (2001)

Create color time-frequency plots from eha results.

Generate noise surrogates from a theoretical power spectrum

Generate cross-plot with kernel density estimates on axes

Monte Carlo simulation for TimeOpt

'Dynamic window' moving assessment of maxima and minima in stratigraphic series

'Dynamic window' moving average, median and variance of stratigraphic series

timeOptTemplatePlot

TimeOptTemplatePlot: Generate summary figure for TimeOptTemplate analyses

Simple periodogram

timeOptTemplateSim

Simulations for timeOptTemplate

Prewhiten stratigraphic series with autoregressive filter, order selected by Akaike Information Criterion

Astrochronologic testing via the obliquity amplitude modulation approach of Zeeden et al. (2019 submitted).

Ar/Ar Geochronology: Generate an Ar/Ar age spectrum and calculate step-heating plateau age.

Frequency-domain minimal tuning: Use interactive graphical interface and sorting to track frequency drift

A tool to interactively trace peak trajectories on plots

Remove missing entries, sort data, average duplicates

Astrochronologic testing via the precession amplitude modulation approach of Zeeden et al. (2015).

Apply Taner bandpass or lowpass filter to stratigraphic series

Read data matrix from file

Read data from file

Evaluate power spectrum false positive rates via Monte Carlo simulation

Identify minima of troughs in series, filter at desired threshold value

Remove outliers from stratigraphic series

Example stratigraphic model series

Prewhiten stratigraphic series with AR1 filter, using 'standard' or unbiased estimate of rho

Tune stratigraphic series

Bioturbation removal function following the approach of Liu et al (2021)

Ar/Ar Geochronology: calculate weighted mean age, age uncertainty, and other associated statistics/plots (with interactive graphics for data culling).

Generate power law (1/f) noise surrogates

Set default plotting parameters for vertical stratigraphic plots

Integrate sedimentation rate curve to obtain time-space map

Identify optimal spatial/temporal shift to maximize correlation between two stratigraphic/time series.

Summary statistics for stratigraphic series

Estimate correlation coefficient and significance for serially correlated data

Remove stratigraphic levels that contain one or more NAs

Resample stratigraphic series

Generate phase-randomized surrogate series as in Ebisuzaki (1997)

Calculate all possible difference and combinations tones

Synthesize stratigraphy from forcing function

timeOptSimPwrLaw

Monte Carlo simulation for TimeOpt, using power law (1/f) noise

Dynamically explore cross-plot, zoom-in into specified region

Write tab-delimited file

timeOptTemplate

TimeOpt analysis using variable sedimentation models

Frequency-domain minimal tuning: Use interactive graphical interface to trace frequency drift

A tool to interactively select points to track peak trajectories on plots

Remove outliers from stratigraphic series