fitModel <- function(iter = 5, ...){

    error = TRUE

    i = 1

    while ((error) && (i < 5)){

        model <- try(train(...))

        error <- class(model) == "try-error"

        i = i + 1

    }

    if (i == iter) {

        model = NA

        warning("Algorithm did not converge. Returning NAs")

    }

    return(model)

}

predictModel <- function(model, newdata){

    if (class(model) == "train"){

        predicted = predict.train(model, newdata = newdata)    

        ts.acc = sum(test.cond == as.numeric(predicted)) / length(test.cond)

    }

    if (class(model) != "train"){ 

        ts.acc = NA

    }

    return(ts.acc)

}

foldIndex <- function(data, nSamp = NULL, nFolds = 5, repeats = 2){

    if(is.null(nSamp)) n = nrow(data)

    else n = nSamp

    indIn <- indOut <- list()

    for (j in 1:repeats){

        tmpIn = createFolds(1:n, k = nFolds, list = TRUE, returnTrain = TRUE)

        tmpOut = lapply(tmpIn, function(x)c(1:n)[-x])

        indIn = c(indIn, tmpIn)

        indOut = c(indOut, tmpOut)

    }

    nms = paste(rep(paste("Fold", 1:nFolds, sep = ""), repeats), 

                rep(paste(".Rep", 1:repeats, sep = ""), c(rep(nFolds, repeats))), sep = "")

    names(indIn) <- names(indOut) <- nms

    return(list(indexIn = indIn, indexOut = indOut))

}