fmddisc {GRTo} | R Documentation |
Analysis of Discontinuities in Frequency Magnitude Distributions
Description
This function finds significant discontinuities in Frequency Magnitude Distributions (FMD).
Usage
fmddisc(file, header = FALSE, colid = 1, nrep = 200, title = "fmddisc")
Arguments
file |
filename of the file to be loaded |
header |
whether |
colid |
field number for the magnitude values in |
nrep |
number of replicates for the bootstrap |
title |
main title for the plot |
Details
This function reads magnitude values in the field which number is indicated by colid
in file
.
The function returns values of significant magnitude discontinuities (e. g. deviations from linearity) in the FMD. A bootstrap procedure is used to obtain the 90% confidence interval for magnitude
discontinuities. We assumed the distribution of the nrep
bootstrap replicates is not skewed. Therefore, the 90% confidence interval is simply formed by taking 5% and 95% quantiles of the bootstrap replicates as the lower and upper bound of the interval respectively. These values and the 50% quantile (median) are returned in a list by the function.
The function also returns bootstrap mean and bootstrap standard-error (standard deviation of bootstrap replicate estimates). The bootstrap margin of errors at the 90% normal confidence level is returned as the result of 1.645 \* bootstrap standard-error.
The function produces a plot showing the FMD and histograms of magnitude values for the significant
discontinuities in the FMD. The plot is stored into a file with name file
\_disc.png (png format file).
Values of counts in histograms are controlled by the number of replicates nrep
that are
used.
Value
This function returns a list containing the following components:
quant1 |
the 5%, 50% and 95% quantiles of the bootstrap replicates for the main discontinuity |
valid |
the numbers of valid replicates |
bmean |
the bootstrap mean values |
bse |
the bootstrap standard-error values |
bme |
the bootstrap margin of errors values |
quant2 |
the 5%, 50% and 95% quantiles of the bootstrap replicates for the auxiliary discontinuity |
Note
Thanks to Scott Kostyshak for telling us about the extra bootstrap package dependency. GRTo version 1.2 fixes this issue.
Author(s)
Daniel Amorese
References
D. Amorese, "Applying a change-point detection method on frequency-magnitude distributions", Bull. seism. Soc. Am. (2007) 97, doi:10.1785\/0120060181
Examples
fmddisc(file=system.file("extdata","IDYLLdeep.data.txt",package="GRTo"),
header=FALSE,colid=15,nrep=200,"FMD mag discontinuities")