Alphabetic Content Ratio of Text — content

The fraction of a string's non-space characters that are letters. A domain-agnostic measure of how much of a unit is prose rather than numbers, punctuation, or symbols: real sentences score near 1, while citation fragments, reference lists, number tables, and identifiers ("OJ No L 297, 24.11.1979, p. 1.", "doi:10.1007/...") score low. Used by the min_content filters of segment() and topics().

Usage

content_ratio(text)

Arguments

text: A character vector.

Value

A numeric vector in [0, 1]; empty or space-only elements score 0.

Examples

content_ratio(c("A real sentence here.", "OJ No L 297, 24.11.1979, p. 1."))
#> [1] 0.9444444 0.2500000