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1 ########################################################
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2 #
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3 # creation date : 25/10/16
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4 # last modification : 25/10/16
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5 # author : Dr Nicolas Beaume
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6 #
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7 ########################################################
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8
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9 suppressWarnings(suppressMessages(library(GA)))
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10 library("miscTools")
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11 library(rpart)
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12 suppressWarnings(suppressMessages(library(randomForest)))
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13 library(e1071)
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14 suppressWarnings(suppressMessages(library(glmnet)))
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15 ############################ helper functions #######################
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16
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17 ##### Genetic algorithm
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18 optimizeOneIndividual <- function(values, trueValue) {
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19 # change the value into a function
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20 f <- function(w) {sum(values * w/sum(w))}
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21 fitness <- function(x) {1/abs(trueValue-f(x))}
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22 resp <- ga(type = "real-valued", fitness = fitness, min = rep(0, length(values)), max = rep(1, length(values)),
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23 maxiter = 1000, monitor = NULL, keepBest = T)
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24 resp@solution <- resp@solution/sum(resp@solution)
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25 return(resp)
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26 }
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27
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28 optimizeWeight <- function(values, trueValue, n=1000) {
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29 fitnessAll <- function(w) {
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30 predicted <- apply(values, 1, weightedPrediction.vec, w)
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31 return(mean(r2(trueValue, predicted)))
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32 #return(mean(1/abs(trueValue-predicted)))
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33 }
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34 resp <- ga(type = "real-valued", fitness = fitnessAll, min = rep(0, ncol(values)), max = rep(1, ncol(values)),
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35 maxiter = n, monitor = NULL, keepBest = T)
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36 resp@solution <- resp@solution/sum(resp@solution)
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37 return(resp)
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38 }
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39
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40 weightedPrediction <- function(classifiers, w) {
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41 if(length(w) > ncol(classifiers)) {
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42 warning("more weights than classifiers, extra weigths are ignored")
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43 w <- w[1:ncol(classifiers)]
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44 } else if(length(w) < ncol(classifiers)) {
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45 warning("less weights than classifiers, extra classifiers are ignored")
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46 classifiers <- classifiers[,1:length(w)]
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47 }
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48 prediction <- NULL
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49 prediction <- c(prediction, apply(classifiers, 1, weightedPrediction.vec, w))
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50 return(prediction)
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51 }
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52
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53 weightedPrediction.vec <- function(values, w) {
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54 return(sum(values * w/sum(w)))
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55 }
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56
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57 ##### meta-decision tree
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58
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59 tuneTree <- function(data, target) {
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60 data <- data.frame(data, target=target)
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61 size <- nrow(data)
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62 xerror <- NULL
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63 split <- 1:ceiling(size/5)
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64 leafSize <- 1:ceiling(size/10)
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65 xerror <- matrix(rep(-1, length(split)*length(leafSize)), ncol=length(leafSize))
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66 cp <- matrix(rep(-1, length(split)*length(leafSize)), ncol=length(leafSize))
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67 for(i in 1:length(split)) {
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68 for(j in 1:length(leafSize)) {
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69 op <- list(minsplit=split[i], minbucket=leafSize[j])
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70 tree <- rpart(target ~., data=data, control=op, method="anova")
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71 xerror[i,j] <- tree$cptable[which.min(tree$cptable[,"xerror"]),"xerror"]
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72 cp[i,j] <- tree$cptable[which.min(tree$cptable[,"xerror"]),"CP"]
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73 }
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74 }
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75 index <- which(xerror==min(xerror), arr.ind = T)
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76 op <- list(minsplit=split[index[1]], minbucket=leafSize[index[2]], cp=cp[index[1], index[2]])
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77 return(op)
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78 }
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79
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80 ###### meta-LASSO
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81 # create fold by picking at random row indexes
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82 createFolds <- function(nbObs, n) {
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83 # pick indexes
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84 index <- sample(1:n, size=nbObs, replace = T)
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85 # populate folds
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86 folds <- NULL
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87 for(i in 1:n) {
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88 folds <- c(folds, list(which(index==i)))
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89 }
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90 return(folds)
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91 }
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92
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93 searchParamLASSO <- function(genotype, phenotype, alpha=seq(0,1,0.1), n=7) {
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94 folds <- createFolds(nrow(genotype), n = n)
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95 acc <- NULL
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96 indexAlpha <- 1
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97 for(a in alpha) {
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98 curAcc <- NULL
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99 for(i in 1:n) {
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100 train <- genotype[-folds[[i]],]
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101 test <- genotype[folds[[i]],]
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102 phenoTrain <- phenotype[-folds[[i]]]
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103 phenoTest <- phenotype[folds[[i]]]
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104 cv <- cv.glmnet(x=as.matrix(train), y=phenoTrain, alpha=a)
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105 model <- glmnet(x=as.matrix(train), y=phenoTrain, alpha=a, lambda = cv$lambda.1se)
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106 pred <- predict(model, test, type = "response")
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107 curAcc <- c(curAcc, r2(phenoTest, pred))
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108 }
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109 acc <- c(acc, mean(curAcc))
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110 }
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111 names(acc) <- alpha
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112 return(as.numeric(names(acc)[which.max(acc)]))
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113 }
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114
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115 ###### meta-random forest
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116
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117 searchParamRF <- function(genotype, phenotype, rangeNtree, mtry=ncol(genotype)) {
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118 n <- ceiling(nrow(genotype)/3)
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119 indexTest <- sample(1:nrow(genotype), size=n)
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120 train <- genotype[-indexTest,]
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121 test <- genotype[indexTest,]
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122 phenoTrain <- phenotype[-indexTest]
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123 phenoTest <- phenotype[indexTest]
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124 acc <- NULL
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125 indexNtree <- 1
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126 for(ntree in rangeNtree) {
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127 model <- randomForest(x=train, y=phenoTrain, ntree = ntree, mtry = mtry)
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128 pred <- predict(model, test)
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129 acc <- c(acc, r2(phenoTest, pred))
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130 }
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131 names(acc) <- rangeNtree
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132 best <- which.max(acc)
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133 return(as.numeric(names(acc)[best]))
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134 }
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135
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136 ###### meta-SVM
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137 searchParamSVM <- function(train, target, kernel="radial") {
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138 # tuning parameters then train
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139 model <- NULL
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140 switch(kernel,
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141 sigmoid={
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142 tune <- tune.svm(train, target, gamma = 10^(-6:-1), cost = 10^(0:2), kernel="sigmoid");
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143 g <- tune$best.parameters[[1]];
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144 c <- tune$best.parameters[[2]];
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145 model <- svm(x=train, y=target, gamma = g, cost = c, kernel = "sigmoid")},
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146 linear={
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147 tune <- tune.svm(train, target, cost = 10^(0:2), kernel="linear");
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148 c <- tune$best.parameters[[1]];
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149 model <- svm(x=train, y=target, cost = c, kernel = "linear")},
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150 polynomial={
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151 tune <- tune.svm(train, target, gamma = 10^(-6:-1), cost = 10^(0:2), degree = 0:4, coef0 = 0:3, kernel="polynomial");
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152 d <- tune$best.parameters[[1]];
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153 g <- tune$best.parameters[[2]];
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154 coef <- tune$best.parameters[[3]];
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155 c <- tune$best.parameters[[4]];
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156 model <- svm(x=train, y=target, gamma = g, cost = c, kernel = "polynomial", degree = d, coef0 = coef)},
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157 {
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158 tune <- tune.svm(train, target, gamma = 10^(-6:-1), cost = 10^(0:3), kernel="radial");
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159 g <- tune$best.parameters[[1]];
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160 c <- tune$best.parameters[[2]];
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161 model <- svm(x=train, y=target, gamma = g, cost = c, kernel = "radial")}
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162 )
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163 return(model)
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164 }
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165
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166 #################### upper level functions #####################
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167
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168 aggregateDT <- function(classifiers, target=NULL, prediction=F, model=NULL, out) {
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169 if(!prediction) {
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170 treeParam <- tuneTree(classifiers, target)
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171 data <- data.frame(classifiers, target)
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172 model <- rpart(target ~., data=data, method = "anova", control = treeParam)
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173 model <- prune(model, cp=treeParam["cp"])
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174 saveRDS(model, out)
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175 } else {
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176 saveRDS(predict(model, data.frame(classifiers)), out)
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177 }
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178 }
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179
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180 aggregateGeneticMean <- function(classifiers, target=NULL, prediction=F, model=NULL, out){
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181 if(!prediction) {
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182 opt <- optimizeWeight(values = classifiers, trueValue = target)
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183 saveRDS(opt@solution, out)
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184 # evaluation of the method
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185 } else {
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186 saveRDS(weightedPrediction.vec(classifiers, model), out)
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187 }
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188 }
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189
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190 aggregateLASSO <- function(classifiers, target=NULL, prediction=F, model=NULL, alpha=NULL, out) {
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191 if(!prediction) {
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192 alpha <- searchParamLASSO(classifiers, target)
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193 cv <- cv.glmnet(x=as.matrix(classifiers), y=target, alpha=alpha)
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194 model <- glmnet(x=as.matrix(classifiers), y=target, alpha=alpha, lambda = cv$lambda.1se)
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195 saveRDS(model, out)
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196 } else {
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197 saveRDS(predict(model, classifiers), out)
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198 }
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199 }
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200
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201 aggregateRF <- function(classifiers, target=NULL, model=NULL, ntree=NULL, prediction=F, out) {
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202 if(!prediction) {
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203 ntree <- searchParamRF(genotype = classifiers, phenotype = target,
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204 rangeNtree = seq(100, 1000, 100))
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205 model <- randomForest(x=classifiers, y=target, ntree = ntree, mtry = ncol(classifiers))
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206 saveRDS(model, out)
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207 } else {
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208 saveRDS(predict(model, classifiers), out)
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209 }
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210 }
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211
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212 aggregateSVM <- function(classifiers, target=NULL, prediction=F,
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213 model=NULL, c=NULL, g=NULL, d=NULL, coef=NULL, kernel="radial", out) {
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214 if(!prediction) {
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215 model <- searchParamSVM(train = classifiers, target = target, kernel = kernel)
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216 saveRDS(model, out)
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217 } else {
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218 saveRDS(predict(model, classifiers), out)
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219 }
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220 }
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221
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222 ################################### main #############################
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223 # # load argument
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224 cmd <- commandArgs(T)
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225 source(cmd[1])
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226 # check if evaluation is required
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227 evaluation <- F
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228 if(as.integer(doEvaluation) == 1) {
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229 evaluation <- T
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230 con = file(folds)
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231 folds <- readLines(con = con, n = 1, ok=T)
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232 close(con)
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233 folds <- readRDS(folds)
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234 }
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235 # check for model
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236 if(model == "None") {
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237 model <- NULL
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238 prediction <- F
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239 } else {
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240 prediction <- T
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241 con = file(model)
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242 model <- readLines(con = con, n = 1, ok=T)
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243 close(con)
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244 model <- readRDS(model)
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245 }
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246 # load classifiers and phenotype
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247 classifiers <- NULL
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248 classifNames <- NULL
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249 if(lassoPred !="None"){
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250 classifiers <- c(classifiers, lassoPred)
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251 classifNames <- c(classifNames, "lasso")
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252 }
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253 if(rrBLUPPred !="None"){
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254 classifiers <- c(classifiers, rrBLUPPred)
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255 classifNames <- c(classifNames, "rrBLUP")
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256 }
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257 if(rfPred !="None"){
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258 classifiers <- c(classifiers, rfPred)
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259 classifNames <- c(classifNames, "rf")
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260 }
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261 if(svmPred !="None"){
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262 classifiers <- c(classifiers, svmPred)
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263 classifNames <- c(classifNames, "svm")
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264 }
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265 classifPrediction <- NULL
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266 for(classif in classifiers) {
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267 classifPrediction <- c(classifPrediction, list(read.table(classif, sep="\t", h=T)))
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268 }
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269 classifPrediction <- data.frame(classifPrediction)
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270 colnames(classifPrediction) <- classifNames
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271 # phenotype is written as a table (in columns) but it must be sent as a vector for mixed.solve
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272 phenotype <- read.table(phenotype, sep="\t", h=T)[,1]
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273 out <- paste(out, ".rds", sep = "")
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274 # aggregate !
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275 switch(method,
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276 geneticMean={
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277 aggregateGeneticMean(classifiers = classifPrediction, target = phenotype,
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278 out = out, prediction = prediction, model=model)
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279 },
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280 dt={
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281 aggregateDT(classifiers = classifPrediction, target = phenotype,
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282 out = out, prediction = prediction, model=model)
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283 },
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284 lasso={
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285 aggregateLASSO(classifiers = classifPrediction, target = phenotype,
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286 out = out, prediction = prediction, model=model)
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287 },
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288 rf={
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289 aggregateRF(classifiers = classifPrediction, target = phenotype,
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290 out = out, prediction = prediction, model=model)
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291 },
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292 # svm
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293 {aggregateSVM(classifiers = classifPrediction, target = phenotype, kernel = kernel,
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294 out = out, prediction = prediction, model = model)}
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295 )
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296 # return path of the result file to galaxy
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297 cat(paste(out, "\n", sep="")) |