GroupMean | R Documentation |
Calculates some groupwise descriptive statistics.
GroupMean(data, group, weights=NULL, extend=FALSE, elim=FALSE)
GroupSum(data, group, weights=NULL, extend=FALSE)
GroupSD(data, group, weights=NULL, extend=FALSE)
# group mean of a variable
gm(y, cluster, elim=FALSE)
# centering within clusters
cwc(y, cluster)
data |
A numeric data frame |
group |
A vector of group identifiers |
weights |
An optional vector of sample weights |
extend |
Optional logical indicating whether the group means (or sums) should be extended to the original dimensions of the dataset. |
elim |
Logical indicating whether a case in a row should be removed from the calculation of the mean in a cluster |
y |
Variable |
cluster |
Cluster identifier |
A data frame or a vector with groupwise calculated statistics
mitml::clusterMeans
base::rowsum
,
stats::aggregate
,
stats::ave
## Not run:
#############################################################################
# EXAMPLE 1: Group means and standard deviations for data.ma02
#############################################################################
data(data.ma02, package="miceadds" )
dat <- data.ma02[[1]] # select first dataset
#--- group means for read and math
GroupMean( dat[, c("read","math") ], group=dat$idschool )
# using rowsum
a1 <- base::rowsum( dat[, c("read","math") ], dat$idschool )
a2 <- base::rowsum( 1+0*dat[, c("read","math") ], dat$idschool )
(a1/a2)[1:10,]
# using aggregate
stats::aggregate( dat[, c("read","math") ], list(dat$idschool), mean )[1:10,]
#--- extend group means to original dataset
GroupMean( dat[, c("read","math") ], group=dat$idschool, extend=TRUE )
# using ave
stats::ave( dat[, "read" ], dat$idschool )
stats::ave( dat[, "read" ], dat$idschool, FUN=mean )
#--- group standard deviations
GroupSD( dat[, c("read","math") ], group=dat$idschool)[1:10,]
# using aggregate
stats::aggregate( dat[, c("read","math") ], list(dat$idschool), sd )[1:10,]
#############################################################################
# EXAMPLE 2: Calculating group means and group mean centering
#############################################################################
data(data.ma07, package="miceadds")
dat <- data.ma07
# compute group means
miceadds::gm( dat$x1, dat$id2 )
# centering within clusters
miceadds::cwc( dat$x1, dat$id2 )
# evaluate formula with model.matrix
X <- model.matrix( ~ I( miceadds::cwc(x1, id2) ) + I( miceadds::gm(x1,id2) ), data=dat )
head(X)
## End(Not run)
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