diff --git a/README.md b/README.md index 9e2189b2a4d4cecfac3328788220d6442a816640..2866268558f5efb3a5084c4ad5fe6dc610df5585 100644 --- a/README.md +++ b/README.md @@ -1,40 +1,31 @@ VarExp ====== -The R package **VarExp** provides functions for the estimating of the -percentage of phenotypic variance explained by genetic effects, -interaction effects or jointly by both effects. This suite of functions -are useful for meta-analysis designs where pooling individual genotype -data is challenging. A pre-print article related to this work is -available [here](bioRkiv%20link) +The R package **VarExp** provides functions for the estimating of the percentage of phenotypic variance explained by genetic effects, interaction effects or jointly by both effects. This suite of functions are useful for meta-analysis designs where pooling individual genotype data is challenging. A pre-print article related to this work is available [here](bioRkiv%20link) Prerequisite ------------ -Library -[**Rcurl**](https://cran.r-project.org/web/packages/RCurl/index.html) is -required to run **VarExp** +Library [**Rcurl**](https://cran.r-project.org/web/packages/RCurl/index.html) is required to run **VarExp** Installation ------------ -For now, **VarExp** can be installed only using package source. In R, -after setting your working directory to *VarExp\_0.1.0.tar.gz* location, -type: +For now, **VarExp** can be installed only using package source. In R, after setting your working directory to *VarExp\_0.1.0.tar.gz* location, type: - install.packages("VarExp_0.1.0.tar.gz", repos = NULL, type = "source") +``` r +install.packages("VarExp_0.1.0.tar.gz", repos = NULL, type = "source") +``` Input format ------------ Two input files are required. -- A file providing the meta-analysis results with the following - mandatory columns: +- A file providing the meta-analysis results with the following mandatory columns: - the rs identifier of the variant - the chromosome number on which the variant is - - the physical position of the variant (currently in NCBI Build - B37) + - the physical position of the variant (currently in NCBI Build B37) - the tested allele of the variant - the frequency of the allele A0 - the regression coefficient of the main genetic effect @@ -54,9 +45,7 @@ Two input files are required. ## rs7538305 1 824398 C 0.15379 0.054950590 -0.04494799 ## rs28613513 1 1112810 T 0.05358 -0.001334013 0.10294423 -- A file providing the summary statistics for the outcome and the - exposure in each individual cohort included in the meta-analysis. - Mandatory columns of this file are: +- A file providing the summary statistics for the outcome and the exposure in each individual cohort included in the meta-analysis. Mandatory columns of this file are: - the identifier of the cohort - the sample size of the cohort - the phenotype mean in the cohort @@ -73,44 +62,44 @@ Two input files are required. ## 4 10000 1.342020 3.151429 1.999943 1.256718 ## 5 10000 1.385564 3.153274 2.002401 1.235129 -Note that in the case of a binary exposure, the two latter columns can -be replaced by a single column providing the count of exposed -individuals in each cohort. +Note that in the case of a binary exposure, the two latter columns can be replaced by a single column providing the count of exposed individuals in each cohort. Short tutorial -------------- Data used in this tutorial are included in the ***VarExp*** package. - # Load the package - library(VarExp) +``` r +# Load the package +library(VarExp) - # Load the meta-analysis summary statistics file - data(GWAS) +# Load the meta-analysis summary statistics file +data(GWAS) - # Load the cohort description file - data(COHORT) +# Load the cohort description file +data(COHORT) - # Compute the genotype correlation matrix from the reference panel - C <- getGenoCorMatrix(GWAS$RSID, GWAS$CHR, GWAS$POS, GWAS$A0, "EUR", pruning = FALSE) +# Compute the genotype correlation matrix from the reference panel +C <- getGenoCorMatrix(GWAS$RSID, GWAS$CHR, GWAS$POS, GWAS$A0, "EUR", pruning = FALSE) - # Make sure SNPs in the GWAS data and in the correlation matrix match - # Necessary if pruning = TRUE, otherwise should have no effect - GWAS <- checkInput(GWAS, colnames(C)) +# Make sure SNPs in the GWAS data and in the correlation matrix match +# Necessary if pruning = TRUE, otherwise should have no effect +GWAS <- checkInput(GWAS, colnames(C)) - # Retrieve mean and variance of the exposure and the phenotype - # from individual cohort summary statistics - parsY <- calculateParamsFromIndParams(COHORT$PHENO_N, COHORT$PHENO_Mean, COHORT$PHENO_SD) - parsE <- calculateParamsFromIndParams(COHORT$PHENO_N, COHORT$EXPO_Mean, COHORT$EXPO_SD) +# Retrieve mean and variance of the exposure and the phenotype +# from individual cohort summary statistics +parsY <- calculateParamsFromIndParams(COHORT$PHENO_N, COHORT$PHENO_Mean, COHORT$PHENO_SD) +parsE <- calculateParamsFromIndParams(COHORT$PHENO_N, COHORT$EXPO_Mean, COHORT$EXPO_SD) - # Re-scale effect sizes as if estimated in a standardized model - std_betaG <- standardizeBeta(GWAS$MAIN_EFFECT, GWAS$INT_EFFECT, GWAS$FREQ_A0, parsE[1], parsE[2], type = "G") - std_betaI <- standardizeBeta(GWAS$MAIN_EFFECT, GWAS$INT_EFFECT, GWAS$FREQ_A0, parsE[1], parsE[2], type = "I") +# Re-scale effect sizes as if estimated in a standardized model +std_betaG <- standardizeBeta(GWAS$MAIN_EFFECT, GWAS$INT_EFFECT, GWAS$FREQ_A0, parsE[1], parsE[2], type = "G") +std_betaI <- standardizeBeta(GWAS$MAIN_EFFECT, GWAS$INT_EFFECT, GWAS$FREQ_A0, parsE[1], parsE[2], type = "I") - # Estimation of the fraction of variance explained - fracG <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "G") - fracI <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "I") - fracJ <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "J") +# Estimation of the fraction of variance explained +fracG <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "G") +fracI <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "I") +fracJ <- calculateVarFrac(std_betaG, std_betaI, C, parsY[2], sum(COHORT$PHENO_N), "J") +``` Bug report / Help ----------------- @@ -120,13 +109,9 @@ Please open an issue if you find a bug. Code of conduct --------------- -Please note that this project is released with a [Contributor Code of -Conduct](https://gitlab.pasteur.fr/statistical-genetics/VarExp/blob/master/code-of-conduct.md). -By participating in this project you agree to abide by its terms. +Please note that this project is released with a [Contributor Code of Conduct](https://gitlab.pasteur.fr/statistical-genetics/VarExp/blob/master/code-of-conduct.md). By participating in this project you agree to abide by its terms. License ------- -This project is licensed under the MIT License - see the -[LICENSE.md](https://gitlab.pasteur.fr/statistical-genetics/VarExp/blob/master/LICENSE) -file for details +This project is licensed under the MIT License - see the [LICENSE.md](https://gitlab.pasteur.fr/statistical-genetics/VarExp/blob/master/LICENSE) file for details