| Type: | Package | 
| Title: | Truncated Rank Correlation | 
| Version: | 0.2 | 
| Date: | 2025-04-15 | 
| Maintainer: | Donghyeon Yu <dyu@inha.ac.kr> | 
| Description: | A new measure of similarity between a pair of mass spectrometry (MS) experiments, called truncated rank correlation (TRC). To provide a robust metric of similarity in noisy high-dimensional data, TRC uses truncated top ranks (or top m-ranks) for calculating correlation. Truncated rank correlation as a robust measure of test-retest reliability in mass spectrometry data. For more details see Lim et al. (2019) <doi:10.1515/sagmb-2018-0056>. | 
| License: | GPL-2 | GPL-3 [expanded from: GPL (≥ 2)] | 
| URL: | https://sites.google.com/site/dhyeonyu/software | 
| Packaged: | 2025-04-22 21:27:10 UTC; dyu | 
| NeedsCompilation: | yes | 
| Repository: | CRAN | 
| Date/Publication: | 2025-04-24 17:20:02 UTC | 
| Author: | Johan Lim [aut], Donghyeon Yu [aut, cre], Hsun-chih Kuo [aut], Hyungwon Choi [aut], Scott Walmsley [aut] | 
Kendall's tau for two vector observations
Description
This function calculates the Kendall's tau for two vector observations for the purpose of checking inner calculation.
Usage
k_tau(X,Y)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
Details
Kendall's tau for two vector observations.
Value
| tau | A calculated Kendall's tau value. | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
# Kendall's tau
ktau <- k_tau(S1,S2)
ktau
Procedure for estimating the null distribution of the TRC tau with the m value chosen by the proposed rule.
Description
Procedure for estimating the null distribution of the TRC tau with the m value chosen by the proposed rule.
Usage
null_perm(X,Y,nperm=1000,start=3,range_m=0.5,span=0.5,seed=21,all_m=FALSE)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
| nperm | the number of permutations to estimate the null distribution (default: 1000). | 
| start | A lower bound of a search region for the threshold rank m (default: 3). | 
| range_m | A proportion of length of X for specifying the end of the search region for m (default: 0.8). | 
| span | A parameter alpha which controls the degree of smoothing in loess function. | 
| seed | An initial seed for the permutation. | 
| all_m | a logical flag for returning permuted TRC tau values for all m values (default: FALSE). | 
Details
Null distributions of the TRC tau with a given m value, the Kendall's tau, and Pearson's correlation are estimated by the permuted samples.
Value
| perm_trc | A vector of TRC tau values from the permuted samples with the m value chosen by the proposed rule. | 
| hist_m | A vector of the chosen m values for permutations. | 
| perm_ktau | A vector of Kendall's tau values from the permuted samples. | 
| perm_rho | A vector of Pearson's correlation values from the permuted samples. | 
| perm_trc_all_m | A matrix of permuted TRC tau values for all m values, in which each column stores the permuted TRC tau values for corresponding m value. | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
null_res = null_perm(S1,S2,nperm=1000,start=3,range_m=0.5,span=0.2,seed=21,all_m=FALSE)
Procedure for estimating the null distribution of the TRC tau with a given m value
Description
Procedure for estimating the null distribution of the TRC tau with a given m value.
Usage
null_perm_m0(X,Y,nperm=1000,m=5,seed=21)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
| nperm | the number of permutations to estimate the null distribution (default: 1000). | 
| m | A rank threshold for the calculation of TRC tau (default: 5). | 
| seed | An initial seed for the permutation. | 
Details
Null distribution of the TRC tau with a given m value is estimated by the permuted samples.
Value
| perm_tau | A vector of calculated TRC tau values from the permuted samples | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
null_res = null_perm_m0(S1,S2,nperm=1000,m=5,seed=21)
Pearson's correlation for two vector observations
Description
This function calculates the Pearson's correlation for two vector observations for the purpose of checking inner calculation.
Usage
rho(X,Y)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
Details
Pearson's correlation for two vector observations.
Value
| rho | A calculated Pearson's correlation value. | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
# Pearson's correlation
pcor = rho(S1,S2)
pcor
Procedure for calculating p-values
Description
Procedure for calculating p-values of Pearson's rho, Kendall's tau, TRC tau for two-sided test for the null hypothesis correaltion is equal to 0 based on the estimated null distribution by permutation.
Usage
trc_cor_test(X,Y, nperm=10000,start=3,range_m=0.8, span=0.5, seed=21, m0=NULL)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
| nperm | the number of permutations to estimate the null distribution (default: 10000). | 
| start | A lower bound of a search region for the threshold rank m (default: 3). | 
| range_m | A proportion of length of X for specifying the end of the search region for m (default: 0.8). | 
| span | A parameter alpha which controls the degree of smoothing in loess function (default: 0.5). | 
| seed | An initial seed for the permutation (default: 21). | 
| m0 | a specific m value for p-value of the TRC tau with m (defalut: NULL (not reported)). | 
Details
The p-values are caculated based on the estimated null distributions of the TRC tau with a given m value, the Kendall's tau, and Pearson's correlation with the permuted samples, respectively.
Value
| measure | a vector of calculated Pearson's rho, Kendall's tau, and TRC tau with m chosen by the proposed rule if m0 = NULL; a vector of calculated Pearson's rho, Kendall's tau, TRC tau with m0, TRC tau with m chosen by the proposed rule if m0 is specified. | 
| p_val | a vector of p-values for Pearson's rho, Kendall's tau, and TRC tau with m chosen by the proposed rule if m0 = NULL; a vector of p-values for Pearson's rho, Kendall's tau, TRC tau with m0, TRC tau with m chosen by the proposed rule if m0 is specified. | 
| chs_m | the chosen m value by the proposed procedure. | 
| mean_perm_trc | a mean value of the estimated null distribution of TRC tau by permutation. | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
trc_cor_test(S1,S2, nperm=1000,start=3,range_m=0.8, span=0.2, seed=21, m0=NULL)
Procedure for the choice of m for the TRC tau
Description
Procedure for the choice of m for the TRC tau.
Usage
trc_m_search(X,Y,start=3,range_m=0.8,span=0.3)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
| start | A lower bound of a search region for the threshold rank m (default: 3). | 
| range_m | A proportion of length of X for specifying the end of the search region for m (default: 0.8). | 
| span | A parameter alpha which controls the degree of smoothing in loess function. | 
Details
The thresholding rank m is chosen by the proposed procedure in Lim et al. (2019).
Value
| tau | A calculated TRC tau value with the chosen m value (chs_m). | 
| chs_m | the chosen m value. | 
| km_tau_vec | A vector of calculated k_m * TRC tau values for the given values of m [start, floor(range_m*n)] | 
| km_tau_loess | A fitted values by the local regression with loess function for km_tau_vec . | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
# tau_m
trc_res = trc_m_search(S1,S2,start=3,range_m=0.8,span=0.2)
trc_res$tau
trc_res$chs_m
Trucated Rank Correlation
Description
TRC tau is a robust corrleation measure based on the truncated rank values.
Usage
trc_tau(X,Y,m=5)
Arguments
| X | An observed data vector from the first condition. | 
| Y | An observed data vector from the second condition. | 
| m | A rank threshold for the calculation of TRC tau. | 
Details
Given a rank threshold m, trc_tau calculates the TRC tau value.
Value
| tau | A calculated TRC tau value. | 
References
Lim, J., Yu, D., Kuo, H., Choi, H., and Walmsely, S. (2019). Truncated Rank Correlation as a robust measure of test-retest reliability in mass spectrometry data. Statistical Applications in Genetics and Molecular Biology, 18(4).
Examples
p = 100
sig_z = 1.15
sig_e = 1
mu_z = 2
mu_e = 8
m0 = 30
S1 = rnorm(p,mean=mu_e,sd=sig_e)
S2 = rnorm(p,mean=mu_e,sd=sig_e)
    
if(m0!=0)
{
   X = mu_z + rnorm(m0,mean=0,sd=sig_z)
   indx = 1:p
   s_indx = sort(sample(indx,m0))
   S1[s_indx] = S1[s_indx] + X
   S2[s_indx] = S2[s_indx] + X
}
      
S1 = exp(S1)
S2 = exp(S2)
tau0 = trc_tau(S1,S2,m=m0)
tau0