Package 'LIStest'

Title: Tests of independence based on the Longest Increasing Subsequence
Description: Tests for independence between X and Y computed from a paired sample (x1,y1),...(xn,yn) of (X,Y), using one of the following statistics (a) the Longest Increasing Subsequence (Ln), (b) JLn, a Jackknife version of Ln or (c) JLMn, a Jackknife version of the longest monotonic subsequence. This family of tests can be applied under the assumption of continuity of X and Y.
Authors: J. E. Garcia and V. A. Gonzalez-Lopez
Maintainer: J. E. Garcia <[email protected]>
License: GPL-2
Version: 2.1
Built: 2024-12-13 06:35:52 UTC
Source: CRAN

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Tests of independence based on the Longest Increasing Subsequence

Description

Tests for independence between X and Y computed from a paired sample (x1,y1), ..., (xn,yn) of (X,Y), using one of the following statistics (a) the Longest Increasing Subsequence (Ln), (b) JLn, a Jackknife version of Ln or (c) JLMn, a Jackknife version of the longest monotonic subsequence. This family of tests can be applied under the assumption of continuity of X and Y.

Details

Package: LIStest
Type: Package
Version: 2.1
Date: 2014-03-12
License: GPL-2

Author(s)

J. E. Garcia and V. A. Gonzalez-Lopez Maintainer: J. E. Garcia <[email protected]>

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010


JLMn statistic, to test independence

Description

It compute the JLMn-statistic, from a bivariate sample of continuous random variables X and Y.

Usage

JLMn(x, y)

Arguments

x, y

numeric vectors of data values. x and y must have the same length.

Details

See subsection 3.3-Main reference. For sample sizes less than 20, the correction introduced in subsection 3.2 from main reference, with c = 0.4 was avoided.

Value

The value of the JLMn-statistic.

Author(s)

J. E. Garcia, V. A. Gonzalez-Lopez

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010

Examples

# mixture of two bivariate normal, one with correlation 0.9 and
# the other with correlation -0.9 
#
N <-100
ro<- 0.90
Z1<-rnorm(N)
Z2<-rnorm(N)
X2<-X1<-Z1
I<-(1:floor(N*0.5))
I2<-((floor(N*0.5)+1):N)
X1[I]<-Z1[I]
X2[I]<-(Z1[I]*ro+Z2[I]*sqrt(1-ro*ro))
X1[I2]<-Z1[I2]
X2[I2]<-(Z1[I2]*(-ro)+Z2[I2]*sqrt(1-ro*ro))
plot(X1,X2)

#calculate the statistic
a<-JLMn(X1,X2)
a

JLn statistic, to test independence

Description

It compute the JLn-statistic, from a bivariate sample of continuous random variables X and Y.

Usage

JLn(x, y)

Arguments

x, y

numeric vectors of data values. x and y must have the same length.

Details

See subsection 3.2.-Main reference. For sample sizes less than 20, the correction introduced in subsection 3.2 from main reference, with c = 0.4 was avoided.

Value

The value of the JLn-statistic.

Author(s)

J. E. Garcia and V. A. Gonzalez-Lopez

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010

Examples

## mixture of two bivariate normal, one with correlation 0.9 and
## the other with correlation -0.9 
#
N <-100
ro<- 0.90
Z1<-rnorm(N)
Z2<-rnorm(N)
X2<-X1<-Z1
I<-(1:floor(N*0.5))
I2<-((floor(N*0.5)+1):N)
X1[I]<-Z1[I]
X2[I]<-(Z1[I]*ro+Z2[I]*sqrt(1-ro*ro))
X1[I2]<-Z1[I2]
X2[I2]<-(Z1[I2]*(-ro)+Z2[I2]*sqrt(1-ro*ro))
plot(X1,X2)

# calculate the statistic
a<-JLn(X1,X2)
a

Longest increasing subsequence for a univariate sample

Description

It compute the size of the longest increasing subsequence from a sample of a (continuous) random variable.

Usage

lis(x)

Arguments

x

numeric vector of data values.

Details

See example 2.1-Main reference.

Value

Integer, the size of the longest increasing subsequence.

Author(s)

J. E. Garcia and V. A. Gonzalez-Lopez

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010

Examples

#see Example 2.1 (reference)
a<-lis(c(3,6,1,7,4,2,5,8))
a

Test for independence between paired samples

Description

Test for independence between X and Y computed from a paired sample (x1,y1),...(xn,yn) of (X,Y), using one of the following statistics (a) the Longest Increasing Subsequence (Ln), (b) JLn, a Jackknife version of Ln or (c) JLMn, a Jackknife version of the longest monotonic subsequence. This family of tests can be applied under the assumption of continuity of X and Y.

Usage

lis.test(x, y, alternative = c("two.sided", "less", "greater"), 
method = c("JLMn", "Ln", "JLn"))

Arguments

x, y

numeric vectors of data values. x and y must have the same length.

alternative

indicates the alternative hypothesis and must be one of "two.sided"(default), "greater" or "less".

method

a character string indicating which statistics is to be used for the test. One of "Ln", "JLn", or "JLMn"(default).

Details

For sample sizes less than 20, the correction introduced in subsection 3.2 from main reference, with c = 0.4 was avoided.

Value

sample.estimate

the value of the statistic.

p.value

the p-value for the test.

alternative

a character string describing the alternative hypothesis.

method

a character string indicating what type of Lis-test was performed.

Author(s)

J. E. Garcia and V. A. Gonzalez-Lopez

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010

Examples

# Example 1
# mixture of two bivariate normal, one with correlation 0.9 
# and the other with correlation -0.9 

N <-100
ro<- 0.90
Z1<-rnorm(N)
Z2<-rnorm(N)
X2<-X1<-Z1
I<-(1:floor(N*0.5))
I2<-((floor(N*0.5)+1):N)
X1[I]<-Z1[I]
X2[I]<-(Z1[I]*ro+Z2[I]*sqrt(1-ro*ro))
X1[I2]<-Z1[I2]
X2[I2]<-(Z1[I2]*(-ro)+Z2[I2]*sqrt(1-ro*ro))
plot(X1,X2)
# calculate the p.value using the default settings (method="JLMn" 
# and alternative="two.sided")
lis.test(X1,X2)
# calculate the p.value using method="JLn" and 
# alternative="two.sided".
lis.test(X1,X2,method="JLn")
#
# Example 2: see subsection 4.3.2-Application 2 from main reference.
# (It requires the package VGAM) 
#
#require(VGAM)
#plot(coalminers$BW, coalminers$nBW)
#lis.test(coalminers$BW, coalminers$nBW, 
#alternative = "greater", method = "Ln")
#lis.test(coalminers$BW, coalminers$nBW, 
#alternative = "greater", method = "JLn")
#

Ln (Longest Increasing Subsequence) statistic, to test independence

Description

It compute the Ln-statistic, from a bivariate sample of continuous random variables X and Y.

Usage

Ln(x, y)

Arguments

x, y

numeric vectors of data values. x and y must have the same length.

Details

See Section 2.-Main reference.

Value

The value of the Ln-statistic.

Author(s)

J. E. Garcia and V. A. Gonzalez-Lopez

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010

Examples

## mixture of two bivariate normal, one with correlation 
## 0.9 and  the other with correlation -0.9 
#
N <-100
ro<- 0.90
Z1<-rnorm(N)
Z2<-rnorm(N)
X2<-X1<-Z1
I<-(1:floor(N*0.5))
I2<-((floor(N*0.5)+1):N)
X1[I]<-Z1[I]
X2[I]<-(Z1[I]*ro+Z2[I]*sqrt(1-ro*ro))
X1[I2]<-Z1[I2]
X2[I2]<-(Z1[I2]*(-ro)+Z2[I2]*sqrt(1-ro*ro))
plot(X1,X2)

# calculate the statistic
a<-Ln(X1,X2)
a

Simulated values for the JLMn statistic

Description

Simulated values for the JLMn statistic under the hypothesis of independence

Format

The format is: List of 200 tables

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010


Simulated values for the JLn statistic

Description

Simulated values for the JLn statistic under the hypothesis of independence.

Format

The format is: List of 200 tables

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010


Simulated values for the Ln statistic

Description

Simulated values for the Ln statistic under the hypothesis of independence

Format

The format is: List of 200 tables

References

J. E. Garcia, V. A. Gonzalez-Lopez, Independence tests for continuous random variables based on the longest increasing subsequence, Journal of Multivariate Analysis (2014), http://dx.doi.org/10.1016/j.jmva.2014.02.010