1#  File src/library/base/R/cut.R
2#  Part of the R package, https://www.R-project.org
3#
4#  Copyright (C) 1995-2018 The R Core Team
5#
6#  This program is free software; you can redistribute it and/or modify
7#  it under the terms of the GNU General Public License as published by
8#  the Free Software Foundation; either version 2 of the License, or
9#  (at your option) any later version.
10#
11#  This program is distributed in the hope that it will be useful,
12#  but WITHOUT ANY WARRANTY; without even the implied warranty of
13#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14#  GNU General Public License for more details.
15#
16#  A copy of the GNU General Public License is available at
17#  https://www.R-project.org/Licenses/
18
19cut <- function(x, ...) UseMethod("cut")
20
21cut.default <-
22    function (x, breaks, labels = NULL, include.lowest = FALSE,
23              right = TRUE, dig.lab = 3L, ordered_result = FALSE, ...)
24{
25    if (!is.numeric(x)) stop("'x' must be numeric")
26    if (length(breaks) == 1L) {
27	if (is.na(breaks) || breaks < 2L)
28	    stop("invalid number of intervals")
29	nb <- as.integer(breaks + 1) # one more than #{intervals}
30	dx <- diff(rx <- range(x, na.rm = TRUE))
31	if(dx == 0) {
32            dx <- if(rx[1L] != 0) abs(rx[1L]) else 1
33            breaks <- seq.int(rx[1L] - dx/1000, rx[2L] + dx/1000,
34                              length.out = nb)
35        } else {
36            breaks <- seq.int(rx[1L], rx[2L], length.out = nb)
37            breaks[c(1L, nb)] <- c(rx[1L] - dx/1000, rx[2L] + dx/1000)
38        }
39    } else nb <- length(breaks <- sort.int(as.double(breaks)))
40    if (anyDuplicated(breaks)) stop("'breaks' are not unique")
41    codes.only <- FALSE
42    if (is.null(labels)) {#- try to construct nice ones ..
43	for(dig in dig.lab:max(12L, dig.lab)) {
44            ## 0+ avoids printing signed zeros as "-0"
45	    ch.br <- formatC(0+breaks, digits = dig, width = 1L)
46	    if(ok <- all(ch.br[-1L] != ch.br[-nb])) break
47	}
48	labels <-
49	    if(ok) paste0(if(right)"(" else "[",
50                          ch.br[-nb], ",", ch.br[-1L],
51                          if(right)"]" else ")")
52	    else paste0("Range_", seq_len(nb - 1L))
53        if (ok && include.lowest) {
54            if (right)
55                substr(labels[1L], 1L, 1L) <- "[" # was "("
56            else
57                substring(labels[nb-1L],
58                          nchar(labels[nb-1L], "c")) <- "]" # was ")"
59        }
60    } else if (is.logical(labels) && !labels)
61        codes.only <- TRUE
62    else if (length(labels) != nb - 1L)
63        stop("lengths of 'breaks' and 'labels' differ")
64    code <- .bincode(x, breaks, right, include.lowest)
65    if(codes.only) code
66    else factor(code, seq_along(labels), labels, ordered = ordered_result)
67}
68
69## called from image.default and for use in packages.
70.bincode <- function(x, breaks, right = TRUE, include.lowest = FALSE)
71    .Internal(bincode(x, breaks, right, include.lowest))
72
73