GRTo (version 1.3)

BBootComp: Bootstrap test for the comparison of Gutenberg-Richter b-values

Description

This function computes Gutenberg-Richter b-values, as well as their uncertainties. The comparison of 2 b-values are performed through a bootstrap test.

Usage

BBootComp(finame1, finame2 = NULL, colid1 = 1, colid2 = 1, hd1 = FALSE, 
hd2 = FALSE, nrep = 5000, alter = c("two.sided", "less", "greater"), 
tm1 = NULL, tm2 = NULL, findtm1 = TRUE, findtm2 = TRUE, plot = FALSE, 
title = "BootComp",oplt="p")

Arguments

finame1

a character string specifying the first file to be loaded

finame2

an optional character string specifying the second file to be loaded. See 'Details'

colid1

field number for the magnitude values in finame1

colid2

an optional field number for the magnitude values in finame2. See 'Details'

hd1

logical. Whether finame1 contains headers or not

hd2

logical. Whether finame2 contains headers or not

nrep

number of replicates for the bootstrap

alter

a character string specifying the alternative hypothesis, must be one of '"two.sided"' (default), '"greater"' or '"less"'. You can specify just the initial letter

tm1

threshold magnitude value for the first data set. If tm1 is NULL and findtm1 is FALSE, the function considers that the data set has been already truncated after the threshold magnitude value (i. e. your data set shows only the linear part of the FMD)

tm2

an optional threshold magnitude value for the second data set. If tm2 is NULL and findtm2 is FALSE, the function considers that the data set has been already truncated after the threshold magnitude value (i. e. your data set shows only the linear part of the FMD)

findtm1

logical. Whether an automatic procedure is engaged to determine the threshold magnitude value tm1 or not

findtm2

logical. Whether an automatic procedure is engaged to determine the threshold magnitude value tm2 or not

plot

logical. If TRUE, a FMD plot is drawn. Default is plot equals FALSE

title

character. The title of the plot. The name for the PNG file that includes the plot begins with title

oplt

character. Option for the plot. If oplt is "p", the FMD displays points (open triangles), else it shows a staircase. This option applies only to the plot of a single FMD: When 2 FMDs are compared, they are always shown with point symbols

Value

A list containing the following components:

val

object of class htest containing the results of the bootstrap test

b1

b-value for the first data set

b2

b-value for the second data set

sd1

standard-error of the b-value for the first data set

sd2

standard-error of the b-value for the second data set

m01

threshold magnitude for the first data set

m02

threshold magnitude for the second data set

a1

a-value for the first data set. This value is not corrected for time, e. g. this is not the seismic productivity per year

a2

a-value for the second data set. This value is not corrected for time, e. g. this is not the seismic productivity per year

Details

if 'finame2' is not NULL, this function compares 2 sets of magnitude values that are contained in 2 different files. Otherwise, only the FMD for data in 'finame1' is analyzed.

References

D. Amorese, "Applying a change-point detection method on frequency-magnitude distributions", Bull. seism. Soc. Am. (2007) 97, doi:10.1785\/0120060181

D. Amorese, J.-R. Grasso and P. A. Rydelek, "On varying b-values with depth: results from computer-intensive tests for Southern California", Geophys. J. Int. (2010) 180, 347-360

See Also

utcomp

Examples

    BBootComp(finame1=system.file("extdata","IDYLLshal.data.txt",package="GRTo"),
    finame2=NULL, colid1=15, colid2=NULL,nrep=200,alter=NULL,findtm1=TRUE,
    findtm2=NULL,plot=TRUE, title="IDYLLWILD", tm1=NULL,tm2=NULL)