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
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
index <- function(x, ...)
{
UseMethod("index")
}
index.default <- function(x, ...)
{
seq_len(NROW(x))
}
index.zoo <- function(x, ...)
{
attr(x, "index")
}
index.ts <- function(x, ...)
{
xtsp <- tsp(x)
seq(xtsp[1], xtsp[2], by = 1/xtsp[3])
}
time.zoo <- function(x, ...)
{
index(x)
}
"index<-" <- function(x, value)
{
UseMethod("index<-")
}
"time<-" <- function(x, value)
{
UseMethod("time<-")
}
"index<-.zoo" <- function(x, value)
{
if(length(index(x)) != length(value))
stop("length of index vectors does not match")
if(is.unsorted(ORDER(value)))
stop("new index needs to be sorted")
attr(x, "index") <- value
return(x)
}
"time<-.zooreg" <- "index<-.zooreg" <- function(x, value)
{
if(length(index(x)) != length(value))
stop("length of index vectors does not match")
if(is.unsorted(ORDER(value)))
stop("new index needs to be sorted")
## check whether new index still conforms with
## frequency, if not: drop frequency
d <- try(diff(as.numeric(value)), silent = TRUE)
ok <- if(inherits(d, "try-error") || length(d) < 1 || anyNA(d)) FALSE
else {
deltat <- min(d)
dd <- d/deltat
if(identical(all.equal(dd, round(dd)), TRUE)) {
freq <- 1/deltat
if(freq > 1 && identical(all.equal(freq, round(freq)), TRUE)) freq <- round(freq)
identical(all.equal(attr(x, "frequency") %% freq, 0), TRUE)
} else {
FALSE
}
}
if(!ok) {
attr(x, "frequency") <- NULL
class(x) <- class(x)[-which(class(x) == "zooreg")]
}
attr(x, "index") <- value
return(x)
}
"time<-.zoo" <- function(x, value)
{
if(length(index(x)) != length(value))
stop("length of time vectors does not match")
attr(x, "index") <- value
return(x)
}
start.zoo <- function(x, ...)
{
if (length(index(x)) > 0) index(x)[1]
else NULL
}
end.zoo <- function(x, ...)
{
lx <- length(index(x))
if (lx > 0) index(x)[lx]
else NULL
}
|
