matrixStats (version 0.53.1)

rowVars: Variance estimates for each row (column) in a matrix

Description

Variance estimates for each row (column) in a matrix.

Usage

rowVars(x, rows = NULL, cols = NULL, na.rm = FALSE, center = NULL,
  dim. = dim(x), ...)
colVars(x, rows = NULL, cols = NULL, na.rm = FALSE, center = NULL,
  dim. = dim(x), ...)

Arguments

x

A numeric NxK matrix.

rows, cols

A vector indicating subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.

na.rm

If TRUE, missing values are excluded first, otherwise not.

center

(optional) The center, defaults to the row means.

dim.

An integer vector of length two specifying the dimension of x, also when not a matrix.

...

Additional arguments passed to rowMeans() and rowSums().

Value

Returns a numeric vector of length N (K).

See Also

See rowMeans() and rowSums() in colSums().

Examples

# NOT RUN {
set.seed(1)

x <- matrix(rnorm(20), nrow = 5, ncol = 4)
print(x)

# Row averages
print(rowMeans(x))
print(rowMedians(x))

# Column averages
print(colMeans(x))
print(colMedians(x))


# Row variabilities
print(rowVars(x))
print(rowSds(x))
print(rowMads(x))
print(rowIQRs(x))

# Column variabilities
print(rowVars(x))
print(colSds(x))
print(colMads(x))
print(colIQRs(x))


# Row ranges
print(rowRanges(x))
print(cbind(rowMins(x), rowMaxs(x)))
print(cbind(rowOrderStats(x, which = 1), rowOrderStats(x, which = ncol(x))))

# Column ranges
print(colRanges(x))
print(cbind(colMins(x), colMaxs(x)))
print(cbind(colOrderStats(x, which = 1), colOrderStats(x, which = nrow(x))))


x <- matrix(rnorm(2400), nrow = 50, ncol = 40)

# Row standard deviations
d <- rowDiffs(x)
s1 <- rowSds(d) / sqrt(2)
s2 <- rowSds(x)
print(summary(s1 - s2))

# Column standard deviations
d <- colDiffs(x)
s1 <- colSds(d) / sqrt(2)
s2 <- colSds(x)
print(summary(s1 - s2))
# }