grapes-times-times-grapes: Multiplication of list with y, elementwise

In onlineforecast: Forecast Modelling for Online Applications

Multiplication of list with y, elementwise

Description

Multiplication of each element in a list (x) with y

Usage

x %**% y

Arguments

x	a list of matrices, data.frames, etc.
y	a vector, data.frame or matrix

Details

Each element of x is multiplied with y using the usual elementwise '*' operator.

Typical use is when a function, e.g. bspline(), returns a list of matrices (e.g. one for each base spline) and they should individually be multiplied with y (a vector, matrix, etc.).

Since this is intended to be used for forecast models in the transformation stage then there are some percularities:

If the number of columns or the names of the columns are not equal for one element in x and y, then only the columns with same names are used, hence the resulting matrices can be of lower dimensions.

See the example https://onlineforecasting.org/examples/solar-power-forecasting.html where the operator is used.

Value

A list of same length of x

Examples

x <- list(matrix(1:9,3), matrix(9:1,3))
x

y <- matrix(2,3,3)
y

x %**% y

y <- 1:3

x %**% y

# Naming percularity
nams(x[[1]]) <- c("k1","k2","k3")
nams(x[[2]]) <- c("k2","k3","k4")
y <- matrix(2,3,3)
nams(y) <- c("k1","k3","k7")

# Now the only the horizons matching will be used
x %**% y

onlineforecast documentation built on Oct. 12, 2023, 5:15 p.m.