For a dfm object, return the dfm with only the first or last n documents.

# S3 method for dfm
head(x, n = 6L, ...)

# S3 method for dfm
tail(x, n = 6L, ...)

Arguments

x

a dfm object

n

an integer vector of length up to dim(x) (or 1, for non-dimensioned objects). Values specify the indices to be selected in the corresponding dimension (or along the length) of the object. A positive value of n[i] includes the first/last n[i] indices in that dimension, while a negative value excludes the last/first abs(n[i]), including all remaining indices. NA or non-specified values (when length(n) < length(dim(x))) select all indices in that dimension. Must contain at least one non-missing value.

...

arguments to be passed to or from other methods.

Value

A dfm class object corresponding to the subset of documents determined by by n.

Examples

head(data_dfm_lbgexample, 3)
#> Document-feature matrix of: 3 documents, 37 features (54.05% sparse) and 0 docvars. #> features #> docs A B C D E F G H I J #> R1 2 3 10 22 45 78 115 146 158 146 #> R2 0 0 0 0 0 2 3 10 22 45 #> R3 0 0 0 0 0 0 0 0 0 0 #> [ reached max_nfeat ... 27 more features ]
head(data_dfm_lbgexample, -4)
#> Document-feature matrix of: 2 documents, 37 features (54.05% sparse) and 0 docvars. #> features #> docs A B C D E F G H I J #> R1 2 3 10 22 45 78 115 146 158 146 #> R2 0 0 0 0 0 2 3 10 22 45 #> [ reached max_nfeat ... 27 more features ]
tail(data_dfm_lbgexample)
#> Document-feature matrix of: 6 documents, 37 features (54.05% sparse) and 0 docvars. #> features #> docs A B C D E F G H I J #> R1 2 3 10 22 45 78 115 146 158 146 #> R2 0 0 0 0 0 2 3 10 22 45 #> R3 0 0 0 0 0 0 0 0 0 0 #> R4 0 0 0 0 0 0 0 0 0 0 #> R5 0 0 0 0 0 0 0 0 0 0 #> V1 0 0 0 0 0 0 0 2 3 10 #> [ reached max_nfeat ... 27 more features ]
tail(data_dfm_lbgexample, n = 3)
#> Document-feature matrix of: 3 documents, 37 features (54.05% sparse) and 0 docvars. #> features #> docs A B C D E F G H I J #> R4 0 0 0 0 0 0 0 0 0 0 #> R5 0 0 0 0 0 0 0 0 0 0 #> V1 0 0 0 0 0 0 0 2 3 10 #> [ reached max_nfeat ... 27 more features ]