R: Create n-fold cross validation dataset from data frame

format_nfold {precrec} | R Documentation

## Create n-fold cross validation dataset from data frame

### Description

The `format_nfold` function takes a data frame with scores, label, and n-fold columns and convert it to a list for `evalmod` and `mmdata`.

### Usage

    format_nfold(nfold_df, score_cols, lab_col, fold_col)

### Arguments

`nfold_df` | A data frame that contains at least one score column, label and fold columns.
`score_cols` | A character/numeric vector that specifies score columns of `nfold_df`.
`lab_col` | A number/string that specifies the label column of `nfold_df`.
`fold_col` | A number/string that specifies the fold column of `nfold_df`.

### Value

The `format_nfold` function returns a list that contains multiple scores and labels.

### See Also

`evalmod` for calculation evaluation measures. `mmdata` for formatting input data. `join_scores` and `join_labels` for formatting scores and labels with multiple datasets.

### Examples

    ##################################################
    ### Convert dataframe with 2 models and 5-fold datasets
    ###

    ## Load test data
    data(M2N50F5)
    head(M2N50F5)

    ## Convert with format_nfold
    nfold_list1 = format_nfold(nfold_df = M2N50F5, score_cols = c(1, 2),
                              lab_col = 3, fold_col = 4)

    ## Show the list structure
    str(nfold_list1)
    str(nfold_list1$scores)
    str(nfold_list1$labels)

    ##################################################
    ### Speficy a single score column
    ###

    ## Convert with format_nfold
    nfold_list2 = format_nfold(nfold_df = M2N50F5, score_cols = 1,
                               lab_col = 3, fold_col = 4)

    ## Show the list structure
    str(nfold_list2)
    str(nfold_list2$scores)
    str(nfold_list2$labels)

    ##################################################
    ### Use column names
    ###

    ## Convert with format_nfold
    nfold_list3 = format_nfold(nfold_df = M2N50F5,
                               score_cols = c("score1", "score2"),
                               lab_col = "label", fold_col = "fold")

    ## Show the list structure
    str(nfold_list3)
    str(nfold_list3$scores)
    str(nfold_list3$labels)

[Package precrec version 0.9.1 Index]