1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
#############################################################################
## Copyright (c) 2010-2022 Rune Haubo Bojesen Christensen
##
## This file is part of the ordinal package for R (*ordinal*)
##
## *ordinal* is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 2 of the License, or
## (at your option) any later version.
##
## *ordinal* is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## A copy of the GNU General Public License is available at
## <https://www.r-project.org/Licenses/> and/or
## <http://www.gnu.org/licenses/>.
#############################################################################
## This file contains:
## Gradients of densities of common distribution functions on the form
## g[dist], where "dist" can be one of "logis", "norm", and
## "cauchy". These functions are used in Newton-Raphson algorithms
## when fitting CLMs and CLMMs in clm(), clm2(), clmm() and
## clmm2(). Similar gradients are implemented for the gumbel,
## log-gamma, and Aranda-Ordaz distributions.
glogis <- function(x)
### gradient of dlogis
.C("glogis_C",
x = as.double(x),
length(x),
NAOK = TRUE)$x
gnorm <- function(x)
### gradient of dnorm(x) wrt. x
.C("gnorm_C",
x = as.double(x),
length(x),
NAOK = TRUE)$x
gcauchy <- function(x)
### gradient of dcauchy(x) wrt. x
.C("gcauchy_C",
x = as.double(x),
length(x),
NAOK = TRUE)$x
glogisR <- function(x) {
### glogis in R
res <- rep(0, length(x))
isFinite <- !is.infinite(x)
x <- x[isFinite]
isNegative <- x < 0
q <- exp(-abs(x))
q <- 2*q^2*(1 + q)^-3 - q*(1 + q)^-2
q[isNegative] <- -q[isNegative]
res[isFinite] <- q
res
}
gnormR <- function(x)
### gnorm in R
-x * dnorm(x)
gcauchyR <- function(x)
### gcauchy(x) in R
-2*x/pi*(1+x^2)^-2
|
