fprod | R Documentation |
fprod
is a generic function that computes the (column-wise) product of all values in x
, (optionally) grouped by g
and/or weighted by w
. The TRA
argument can further be used to transform x
using its (grouped, weighted) product.
fprod(x, ...)
## Default S3 method:
fprod(x, g = NULL, w = NULL, TRA = NULL, na.rm = .op[["na.rm"]],
use.g.names = TRUE, ...)
## S3 method for class 'matrix'
fprod(x, g = NULL, w = NULL, TRA = NULL, na.rm = .op[["na.rm"]],
use.g.names = TRUE, drop = TRUE, ...)
## S3 method for class 'data.frame'
fprod(x, g = NULL, w = NULL, TRA = NULL, na.rm = .op[["na.rm"]],
use.g.names = TRUE, drop = TRUE, ...)
## S3 method for class 'grouped_df'
fprod(x, w = NULL, TRA = NULL, na.rm = .op[["na.rm"]],
use.g.names = FALSE, keep.group_vars = TRUE,
keep.w = TRUE, stub = .op[["stub"]], ...)
x |
a numeric vector, matrix, data frame or grouped data frame (class 'grouped_df'). |
g |
a factor, |
w |
a numeric vector of (non-negative) weights, may contain missing values. |
TRA |
an integer or quoted operator indicating the transformation to perform:
0 - "na" | 1 - "fill" | 2 - "replace" | 3 - "-" | 4 - "-+" | 5 - "/" | 6 - "%" | 7 - "+" | 8 - "*" | 9 - "%%" | 10 - "-%%". See |
na.rm |
logical. Skip missing values in |
use.g.names |
logical. Make group-names and add to the result as names (default method) or row-names (matrix and data frame methods). No row-names are generated for data.table's. |
drop |
matrix and data.frame method: Logical. |
keep.group_vars |
grouped_df method: Logical. |
keep.w |
grouped_df method: Logical. Retain product of weighting variable after computation (if contained in |
stub |
character. If |
... |
arguments to be passed to or from other methods. If |
Non-grouped product computations internally utilize long-doubles in C, for additional numeric precision.
The weighted product is computed as prod(x * w)
, using a single pass in C. If na.rm = TRUE
, missing values will be removed from both x
and w
i.e. utilizing only x[complete.cases(x,w)]
and w[complete.cases(x,w)]
.
For further computational details see fsum
, which works equivalently.
The (w
weighted) product of x
, grouped by g
, or (if TRA
is used) x
transformed by its (grouped, weighted) product.
fsum
, Fast Statistical Functions, Collapse Overview
## default vector method
mpg <- mtcars$mpg
fprod(mpg) # Simple product
fprod(mpg, w = mtcars$hp) # Weighted product
fprod(mpg, TRA = "/") # Simple transformation: Divide by product
fprod(mpg, mtcars$cyl) # Grouped product
fprod(mpg, mtcars$cyl, mtcars$hp) # Weighted grouped product
fprod(mpg, mtcars[c(2,8:9)]) # More groups..
g <- GRP(mtcars, ~ cyl + vs + am) # Precomputing groups gives more speed !
fprod(mpg, g)
fprod(mpg, g, TRA = "/") # Groupwise divide by product
## data.frame method
fprod(mtcars)
head(fprod(mtcars, TRA = "/"))
fprod(mtcars, g)
fprod(mtcars, g, use.g.names = FALSE) # No row-names generated
## matrix method
m <- qM(mtcars)
fprod(m)
head(fprod(m, TRA = "/"))
fprod(m, g) # etc..
## method for grouped data frames - created with dplyr::group_by or fgroup_by
mtcars |> fgroup_by(cyl,vs,am) |> fprod()
mtcars |> fgroup_by(cyl,vs,am) |> fprod(TRA = "/")
mtcars |> fgroup_by(cyl,vs,am) |> fselect(mpg) |> fprod()
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