Hop along multiple inputs simultaneously relative to an indexSource:
phop_index() represent the combination
hop_index(), allowing you to iterate
over multiple vectors at once, relative to an
boundaries defined by
hop_index2(.x, .y, .i, .starts, .stops, .f, ...) hop_index2_vec(.x, .y, .i, .starts, .stops, .f, ..., .ptype = NULL) phop_index(.l, .i, .starts, .stops, .f, ...) phop_index_vec(.l, .i, .starts, .stops, .f, ..., .ptype = NULL)
- .x, .y
Vectors to iterate over. Vectors of size 1 will be recycled.
The index vector that determines the window sizes. It is fairly common to supply a date vector as the index, but not required.
There are 3 restrictions on the index:
The size of the index must match the size of
.x, they will not be recycled to their common size.
The index must be an increasing vector, but duplicate values are allowed.
The index cannot have missing values.
- .starts, .stops
Vectors of boundary values that make up the windows to bucket
.stopswill be recycled to their common size, and that common size will be the size of the result. Both vectors should be the same type as
.i. These boundaries are both inclusive, meaning that the slice of
.xthat will be used in each call to
.i >= start & .i <= stopreturns
[function / formula]
If a function, it is used as is.
If a formula, e.g.
~ .x + 2, it is converted to a function. There are three ways to refer to the arguments:
For a single argument function, use
For a two argument function, use
For more arguments, use
This syntax allows you to create very compact anonymous functions.
Additional arguments passed on to the mapped function.
[vector(0) / NULL]
A prototype corresponding to the type of the output.
NULL, the default, the output type is determined by computing the common type across the results of the calls to
If supplied, the result of each call to
.fwill be cast to that type, and the final output will have that type.
.ptypemust be supplied. This is a way to make production code demand fixed types.
A list of vectors. The length of
.ldetermines the number of arguments that
.fwill be called with. If
.lhas names, they will be used as named arguments to
.f. Elements of
.lwith size 1 will be recycled.
A vector fulfilling the following invariants:
vec_size(hop_index2(.x, .y, .starts, .stops)) == vec_size_common(.starts, .stops)
vec_ptype(hop_index2(.x, .y, .starts, .stops)) == list()
vec_size(hop_index2_vec(.x, .y, .starts, .stops)) == vec_size_common(.starts, .stops)
vec_size(hop_index2_vec(.x, .y, .starts, .stops)[]) == 1L
vec_ptype(hop_index2_vec(.x, .y, .starts, .stops, .ptype = ptype)) == ptype
vec_size(phop_index(.l, .starts, .stops)) == vec_size_common(.starts, .stops)
vec_ptype(phop_index(.l, .starts, .stops)) == list()
# Notice that `i` is an irregular index! x <- 1:5 i <- as.Date("2019-08-15") + c(0:1, 4, 6, 7) # Manually create starts/stops. They don't have to be equally spaced, # and they don't have to be the same size as `.x` or `.i`. starts <- as.Date(c("2019-08-15", "2019-08-18")) stops <- as.Date(c("2019-08-16", "2019-08-23")) # The output size is equal to the common size of `.starts` and `.stops` hop_index2(x, i, i, starts, stops, ~data.frame(x = .x, y = .y)) #> [] #> x y #> 1 1 2019-08-15 #> 2 2 2019-08-16 #> #> [] #> x y #> 1 3 2019-08-19 #> 2 4 2019-08-21 #> 3 5 2019-08-22 #>