Numerical and Symbolic Inner Product

Source: R/operators.R

Computes the inner product of two numeric or character arrays.

x %inner% y

Arguments

x

numeric or character array.

y

numeric or character array.

Value

numeric or character.

Details

The inner product between two arrays A and B is computed as: $$C = \sum_{j_1\dots j_n} A_{j_1\dots j_n}B_{j_1\dots j_n}$$

References

Guidotti E (2022). "calculus: High-Dimensional Numerical and Symbolic Calculus in R." Journal of Statistical Software, 104(5), 1-37. doi:10.18637/jss.v104.i05

See also

Other basic arithmetic: %diff%(), %div%(), %dot%(), %kronecker%(), %outer%(), %prod%(), %sum%()

Examples

### numeric inner product 
x <- array(1:4, dim = c(2,2))
x %inner% x
#> [1] 30

### symbolic inner product 
x <- array(letters[1:4], dim = c(2,2))
x %inner% x
#> [1] "(a) * (a) + (b) * (b) + (c) * (c) + (d) * (d)"