classify_cells {scAnnotatR} | R Documentation

## Classify cells from multiple models

### Description

Classify cells from multiple models

### Usage

    classify_cells(
      classify_obj,
      assay,
      slot = NULL,
      classifiers = NULL,
      cell_types = "all",
      chunk_size = 5000,
      path_to_models = "default",
      ignore_ambiguous_result = FALSE,
      cluster_slot = "clusters"
    )

### Arguments

`classify_obj` | the object containing cells to be classified
`assay` | name of assay to use in classify_object
`slot` | type of expression data to use in classify_object. For Seurat object, some available types are: "counts", "data" and "scale.data".
`classifiers` | list of classification models. The model is obtained from train_classifier function or available in current working space. Users may test the model using test_classifier before using this function. If classifiers contain classifiers for sub cell types, classifiers for parent cell type must be indicated first in order to be applied before children classifiers. If classifiers is NULL, the method will use all classifiers in database.
`cell_types` | list of cell types containing models to be used for classification, only applicable if the models have been saved to package.
`chunk_size` | size of data chunks to be predicted separately. This option is recommended for large datasets to reduce running time. Default value at 5000, because smaller datasets can be predicted rapidly.
`path_to_models` | path to the folder containing the list of models. As default value, the pretrained models in the package will be used. If user has trained new models, indicate the folder containing the new_models.rda file.
`ignore_ambiguous_result` | return all ambiguous predictions (multiple cell types) to empty When this parameter turns to TRUE, most probably predicted cell types will be ignored.
`cluster_slot` | name of slot in meta data containing cluster information, in case users want to have additional cluster-level prediction

### Value

the input object with new slots in cells meta data New slots are: predicted_cell_type, most_probable_cell_type, slots in form of [cell_type]_p, [cell_type]_class, and clust_pred (if cluster_slot was provided).

### Examples

    # load small example dataset
    data("tirosh_mel80_example")

    # train one classifier for one cell type, for ex, B cell
    # define genes to use to classify this cell type
    selected_marker_genes_B = c("CD19", "MS4A1", "CD79A")

    # train the classifier
    set.seed(123)
    classifier_b <- train_classifier(train_obj = tirosh_mel80_example,
    assay = 'RNA', slot = 'counts', marker_genes = selected_marker_genes_B,
    cell_type = "b cells", tag_slot = 'active.ident')

    # do the same thing with other cell types, for example, T cells
    selected_marker_genes_T = c("CD4", "CD8A", "CD8B")
    set.seed(123)
    classifier_t <- train_classifier(train_obj = tirosh_mel80_example,
    assay = 'RNA', slot = 'counts', marker_genes = selected_marker_genes_T,
    cell_type = "T cells", tag_slot = 'active.ident')

    # create a list of classifiers
    classifier_ls <- list(classifier_b, classifier_t)

    # classify cells with list of classifiers
    seurat.obj <- classify_cells(classify_obj = tirosh_mel80_example,
    assay = 'RNA', slot = 'counts', classifiers = classifier_ls)

[Package scAnnotatR version 1.0.0 Index]