Monte Carlo consistency test for tuned (time-domain) or depth-domain cycles

Usage

astro_mc(
  constraints,
  age,
  domain = c("time", "depth"),
  anchor = 405,
  anchor_term = "e405",
  scale_range = NULL,
  g4g3_range_kyr = NULL,
  s4s3_range_kyr = NULL,
  age_tol = 5,
  nsim = 2000,
  ptest = c(10000, 28000),
  sampleorb = c("U", "N"),
  s3_uncertainty = c("published", "scaled"),
  seed = NULL,
  block = 1e+05,
  max_attempts = 5e+07,
  verbose = TRUE
)

Arguments

constraints: Measured ranges of the cycles you resolved (named list; each element a numeric vector c(min, max)). Names are astronomical terms: "e405", "e125" (= e130 and e124), "e95" (= e99 and e95), "k+s3" (or "obl", "obliquity"), "k+g5", "k+g2", "k+g4", "k+g3", "prec_short" (= k+g4 and k+g3), "prec_all" (all four precession terms), any other term listed by astro_terms (e.g. "g4-g3", "s4-s3"), or a combination such as "2(g2-g5)". Several terms in one band: "k+g4|k+g3" (all must fit). A peak you cannot assign: "any:k+g5|k+g2" (at least one must fit). Units: kyr when domain = "time", metres when domain = "depth". Required, no default.
age: Approximate age of the record in Ma (numeric): c(min, max), or a single value, which is widened by age_tol Ma on either side. Required, no default.
domain: Domain of the measured cycles (character): "time" for a tuned record (cycles in kyr), "depth" for a depth-domain spectrum (cycles in metres; scale_range must then be given). Default=c("time", "depth"), i.e. "time".
anchor: Period in kyr that was assumed for the tuning target anchor_term when the record was tuned (numeric, > 0); with domain = "time" every predicted period is divided by (sampled period of anchor_term)/anchor. NULL means that the time scale is sampled freely within scale_range. Ignored when domain = "depth". Default=405.
anchor_term: Astronomical term the record was tuned to (character, any name accepted in constraints). Default="e405" (= g2-g5).
scale_range: Range sampled uniformly for the scale factor (numeric vector c(min, max)): the sedimentation rate in m/kyr when domain = "depth" (then required), or the allowed stretch of the time scale when domain = "time" and anchor = NULL (then NULL becomes c(0.9, 1.1)). Default=NULL.
g4g3_range_kyr, s4s3_range_kyr: Not used by the calculation; accepted only for a common interface with other functions (numeric vector c(min, max) in kyr or NULL). Default=NULL.
age_tol: Half-width in Ma of the age range used when age is a single value (numeric, >= 0). Default=5.
nsim: Number of accepted (consistent) Monte Carlo samples to collect (integer, > 0). Default=2000.
ptest: Range of precession constants k to sample uniformly, in years (numeric vector c(min, max)). Default=c(10000, 28000).
sampleorb: How the secular frequencies g2-g5 are sampled (character): "U" uniform within 2 sigma (as in Zeeden et al. 2023) or "N" normal with 1 sigma. Sigma is the Laskar et al. (2011) uncertainty scaled by sqrt(age/100 Myr). Default=c("U", "N"), i.e. "U".
s3_uncertainty: How the uncertainty of s3 is sampled (only when a constraint involves k+s3; character): "published" follows the published CTest code, in which the relative uncertainty is applied as an absolute one in years (s3 is effectively fixed); "scaled" applies it relative to the s3 period, as for g2-g5, giving s3 a realistic spread. Default=c("published", "scaled"), i.e. "published".
seed: Seed of the random number generator (integer), so that the Monte Carlo results can be reproduced; NULL leaves the current random state unchanged. Default=NULL.
block: Number of random draws per iteration of the vectorised search (integer; values below 1000 are raised to 1000). Larger blocks are faster but use more memory. Default=1e5.
max_attempts: Maximum total number of draws before the search stops with an error because fewer than nsim consistent samples were found (numeric, > 0). Default=5e7.
verbose: Print a progress message after each block with accepted samples (logical, TRUE or FALSE). Default=TRUE.

Value

object of class c("astro_mc", "ctest"), so print(), plot() and ctest_earthmoon() work on it