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INPower Readme

  • 1. Download and install R packages mvtnorm if not already installed.
  • 2. Download zip or tar.gz file for your operating system from the download page.
  • 3. Install from R (GUI) package installer or using the install.packages() function, e.g., install.packages(“C:/temp/”, repos=NULL)
  • 4. Load the IN.power package from the GUI or with the command library(IN.Power)
  • 5. Type INPower in R console to access help files and package manual


This function uses the effect sizes for a set of known susceptibility SNPs and the power of detection of these SNPs from the original discovery samples to obtain an estimate of the total number of underlying susceptibility SNP for that trait and the distribution of their effect sizes. The function can further use the estimated number of loci and distribution of effect sizes to evaluate the power for discovery of a future GWAS study (up to three-stage).


Ju-Hyun Park, Nilanjan Chatterjee and William Wheeler


Park J-H, Wacholder S, Gail M, Peters U, Jacobs K, Chanock S, Chatterjee N. Estimation of effect size distribution from genome-wide association studies and implications for future discoveries. Nature Genetics, 2010, 42, pp.570-575.