robustETM-package:
Robust Exponential Tilt Mixture Model
Description
The package robustETM consists of the functions to perform pseudolikelihood based EM test for homogeneity in generalized exponential tilt mixture models.
Testing for homogeneity in generalized exponential titl mixture model
Motivated by analyses of DNA methylation data, we propose a semiparametric mixture model, namely the generalized exponential tilt mixture model,
to account for heterogeneity between differentially methylated and non-differentially methylated subjects in the cancer group, and capture the
differences in higher order moments (e.g. mean and variance) between subjects
in cancer and normal groups. A pairwise pseudolikelihood is constructed
to eliminate the unknown nuisance function. To circumvent boundary and
non-identifiability problems as in parametric mixture models, we modify the
pseudolikelihood by adding a penalty function. In addition, test with simple
asymptotic distribution has computational advantages over permutational
test for high-dimensional genetic and epigenetic data. We propose a pseudolikelihood
based expectation-maximization test, and show the proposed test
follows a simple chi-squared limiting distribution. The methods contains in function sim are:
- The proposed PLEMT test (pseudolikelihood based EM test)
- The t-test
- The modified empirical likelihood ratio test
- The empirical likelihood ratio test
- The logistic regression test
- The Wilcoxon test
- The F test
- The KS test
Details
|
Package: |
| robustETM |
|
Type: |
| robustETM |
|
Version: |
| 1.0 |
|
Date: |
| 2016-03-27 |
|
License: GPL>=2 |
References
Hong, C., Chen Y., Ning Y., Wang S., Wu H. and Carroll R.J. (2016). PLEMT: A novel pseudolikelihood based EM test for homogeneity in generalized exponential tilt mixture model (in preparation).