SpatioTemporal (version 1.1.7)

norm2: Computes Inner Product and Squared 2-norm

Description

dotProd computes the inner (or dot/scalar) product between two vectors. norm2 computes the squared 2-norm of all the elements in a matrix or vector. If the vectors are of unequal length dotProd will give a warning and then truncates the longer vector, discarding any excess elements before the computations.

Usage

norm2(v1)
  dotProd(v1, v2)

Arguments

v1,v2

Two vectors

Value

dotProd returns the inner product of v1 and v2. norm2 returns the squared 2-norm of all elements in v1.

See Also

Other basic linear algebra: blockMult, crossDist, invCholBlock, makeCholBlock, solveTriBlock, sumLog, sumLogDiag

Examples

# NOT RUN {
##Create two vectors of equal length
v1 <- rnorm(10)
v2 <- rnorm(10)

##compute the inner product between the vectors
dotProd(v1,v2)
##or
sum(v1*v2)

##compute the square 2-norm of v1
norm2(v1)
##or
dotProd(v1,v1)
##or
sum(v1*v1)

##If the vectors are of unequal length the longer vector
##gets truncated (with a warning). 
dotProd(v1,c(v2,2))
# }