rray (version 0.1.0)

rray_sum: Calculate the sum along an axis

Description

rray_sum() computes the sum along a given axis or axes. The dimensionality of x is retained in the result.

Usage

rray_sum(x, axes = NULL)

Arguments

x

A vector, matrix, or array to reduce.

axes

An integer vector specifying the axes to reduce over. 1 reduces the number of rows to 1, performing the reduction along the way. 2 does the same, but with the columns, and so on for higher dimensions. The default reduces along all axes.

Value

The result of the reduction as a double with the same shape as x, except along axes, which have been reduced to size 1.

See Also

Other reducers: rray_max, rray_mean, rray_min, rray_prod

Examples

# NOT RUN {
x <- rray(1:10, c(5, 2))

# Reduce the number of rows to 1,
# summing along the way
rray_sum(x, 1)

# Reduce the number of columns to 1,
# summing along the way
rray_sum(x, 2)

# Reduce along all axes, but keep dimensions
rray_sum(x)

# Column-wise proportions
x / rray_sum(x, 1)

# Row-wise proportions
x / rray_sum(x, 2)

# Reducing over multiple axes
# This reduces over the rows and columns
# of each mini-matrix in the 3rd dimension
y <- rray(1:24, c(2, 3, 4))
rray_sum(y, c(1, 2))

# }