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fNobs

Fast (Grouped) Observation Count for Matrix-Like Objects


Description

fNobs is a generic function that (column-wise) computes the number of non-missing values in x, (optionally) grouped by g. It is much faster than sum(!is.na(x)). The TRA argument can further be used to transform x using its (grouped) observation count.

Usage

fNobs(x, ...)

## Default S3 method:
fNobs(x, g = NULL, TRA = NULL, use.g.names = TRUE, ...)

## S3 method for class 'matrix'
fNobs(x, g = NULL, TRA = NULL, use.g.names = TRUE, drop = TRUE, ...)

## S3 method for class 'data.frame'
fNobs(x, g = NULL, TRA = NULL, use.g.names = TRUE, drop = TRUE, ...)

## S3 method for class 'grouped_df'
fNobs(x, TRA = NULL, use.g.names = FALSE, keep.group_vars = TRUE, ...)

Arguments

x

a vector, matrix, data frame or grouped data frame (class 'grouped_df').

g

a factor, GRP object, atomic vector (internally converted to factor) or a list of vectors / factors (internally converted to a GRP object) used to group x.

TRA

an integer or quoted operator indicating the transformation to perform: 1 - "replace_fill" | 2 - "replace" | 3 - "-" | 4 - "-+" | 5 - "/" | 6 - "%" | 7 - "+" | 8 - "*" | 9 - "%%" | 10 - "-%%". See TRA.

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. TRUE drops dimensions and returns an atomic vector if g = NULL and TRA = NULL.

keep.group_vars

grouped_df method: Logical. FALSE removes grouping variables after computation.

...

arguments to be passed to or from other methods.

Details

fNobs preserves all attributes of non-classed vectors / columns, and only the 'label' attribute (if available) of classed vectors / columns (i.e. dates or factors). When applied to data frames and matrices, the row-names are adjusted as necessary.

Value

Integer. The number of non-missing observations in x, grouped by g, or (if TRA is used) x transformed by its number of non-missing observations, grouped by g.

See Also

Examples

## default vector method
fNobs(airquality$Solar.R)                   # Simple Nobs
fNobs(airquality$Solar.R, airquality$Month) # Grouped Nobs

## data.frame method
fNobs(airquality)
fNobs(airquality, airquality$Month)
fNobs(wlddev)                               # Works with data of all types!
head(fNobs(wlddev, wlddev$iso3c))

## matrix method
aqm <- qM(airquality)
fNobs(aqm)                                  # Also works for character or logical matrices
fNobs(aqm, airquality$Month)
 
## method for grouped data frames - created with dplyr::group_by or fgroup_by
library(dplyr)
airquality %>% group_by(Month) %>% fNobs
wlddev %>% group_by(country) %>%
           select(PCGDP,LIFEEX,GINI,ODA) %>% fNobs

collapse

Advanced and Fast Data Transformation

v1.5.3
GPL (>= 2) | file LICENSE
Authors
Sebastian Krantz [aut, cre], Matt Dowle [ctb], Arun Srinivasan [ctb], Laurent Berge [ctb], Dirk Eddelbuettel [ctb], Josh Pasek [ctb], Kevin Tappe [ctb], R Core Team and contributors worldwide [ctb], Martyn Plummer [cph], 1999-2016 The R Core Team [cph]
Initial release
2021-03-05

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