Performs batch effect adjustment using Ratio-A. Here, the variable values are divided by the batch-specific arithmetic mean of the corresponding variable.
Usage
ratioa(x, batch)
Arguments
x
matrix. The covariate matrix. Observations in rows, variables in columns.
batch
factor. Batch variable. Currently has to have levels: '1', '2', '3' and so on.
Value
ratioa returns an object of class ratioa.
An object of class "ratioa" is a list containing the following components:
xadjmatrix of adjusted (training) data
nbatchesnumber of batches
batchbatch variable
References
Luo, J., Schumacher, M., Scherer, A., Sanoudou, D., Megherbi, D., Davison, T., Shi, T., Tong, W., Shi, L., Hong, H., Zhao, C., Elloumi, F., Shi, W., Thomas, R., Lin, S., Tillinghast, G., Liu, G., Zhou, Y., Herman, D., Li, Y., Deng, Y., Fang, H., Bushel, P., Woods, M., Zhang, J. (2010) A comparison of batch effect removal methods for enhancement of prediction performance using maqc-ii microarray gene expression data. The Pharmacogenomics Journal, 10, 278-291.