TADrandomForest {preciseTAD} | R Documentation

## A wrapper function passed to `caret::train` to apply a random forest classification algorithm built and tested on user-defined binned domain data from `createTADdata`.

### Description

A wrapper function passed to `caret::train` to apply a random forest classification algorithm built and tested on user-defined binned domain data from `createTADdata`.

### Usage

    TADrandomForest(
      trainData,
      testData = NULL,
      tuneParams = list(mtry = ceiling(sqrt(ncol(trainData) - 1)), ntree = 500, nodesize =
        1),
      cvFolds = 3,
      cvMetric = "Accuracy",
      verbose = FALSE,
      model = TRUE,
      importances = TRUE,
      impMeasure = "MDA",
      performances = FALSE
    )

### Arguments

`trainData` | Data frame, the binned data matrix to built a random forest classifiers (can be obtained using `createTADdata`). Required.
`testData` | Data frame, the binned data matrix to test random forest classifiers (can be obtained using `createTADdata`). The first column must be a factor with positive class "Yes". Default is NULL in which case no performances are evaluated.
`tuneParams` | List, providing `mtry`, `ntree`, and `nodesize` parameters to feed into `randomForest`. Default is list(mtry = ceiling(sqrt(ncol(trainData) - 1)), ntree = 500, nodesize = 1). If multiple values are provided, then a grid search is performed to tune the model. Required.
`cvFolds` | Numeric, number of k-fold cross-validation to perform in order to tune the hyperparameters. Required.
`cvMetric` | Character, performance metric to use to choose optimal tuning parameters (one of either "Kappa", "Accuracy", "MCC", "ROC", "Sens", "Spec", "Pos Pred Value", "Neg Pred Value"). Default is "Accuracy".
`verbose` | Logical, controls whether or not details regarding modeling should be printed out. Default is TRUE.
`model` | Logical, whether to keep the model object. Default is TRUE.
`importances` | Logical, whether to extract variable importances. Default is TRUE.
`impMeasure` | Character, indicates the variable importance measure to use (one of either "MDA" (mean decrease in accuracy) or "MDG" (mean decrease in gini)). Ignored if importances = FALSE.
`performances` | Logical, indicates whether various performance metrics should be extracted when validating the model on the test data. Ignored if testData = NULL.

### Value

A list containing: 1) a train object from `caret` with model information, 2) a data.frame of variable importance for each feature included in the model, and 3) a data.frame of various performance metrics

### Examples

    # Read in ARROWHEAD-called TADs at 5kb
    data(arrowhead_gm12878_5kb)

    # Extract unique boundaries
    bounds.GR <- extractBoundaries(domains.mat = arrowhead_gm12878_5kb,
                                   preprocess = FALSE,
                                   CHR = c("CHR21", "CHR22"),
                                   resolution = 5000)

    # Read in GRangesList of 26 TFBS
    data(tfbsList)

    # Create the binned data matrix for CHR1 (training) and CHR22 (testing)
    # using 5 kb binning, distance-type predictors from 26 different TFBS from
    # the GM12878 cell line, and random under-sampling
    tadData <- createTADdata(bounds.GR = bounds.GR,
                             resolution = 5000,
                             genomicElements.GR = tfbsList,
                             featureType = "distance",
                             resampling = "rus",
                             trainCHR = "CHR21",
                             predictCHR = "CHR22")

    # Perform random forest using TADrandomForest by tuning mtry over 10 values
    # using 3-fold CV
    tadModel <- TADrandomForest(trainData = tadData[[1]],
                                testData = tadData[[2]],
                                tuneParams = list(mtry = c(2,5,8,10,13,16,18,21,24,26),
                                                ntree = 500,
                                                nodesize = 1),
                                cvFolds = 3,
                                cvMetric = "Accuracy",
                                verbose = TRUE,
                                model = TRUE,
                                importances = TRUE,
                                impMeasure = "MDA",
                                performances = TRUE)

[Package preciseTAD version 1.0.0 Index]