These functions provide the (Euclidean) length of a vector, the vector cross product or angle between two vectors.
resolveVector(len, ...)vectorLength(vector)
vectorCrossProduct(a, b)
angleBetweenVectors(v1, v2)
For vectorLength
, the Euclidean norm or length of the
specified vector, given by sqrt(sum(vector^2))
. For
vectorCrossProduct
, the vector cross product of the two specified
vectors; and for angleBetweenVectors
, the angle (in radians)
between the two specified vectors. The resolveVector
function
concatenates the values given in ...{}
, and if the result is a
vector of length len
then it is returned. If not, NULL
is
returned.
The expected length of the vector.
Elements of the vector, to be concatenated together.
Numeric vectors of any length.
Numeric 3-vectors.
Jon Clayden
Please cite the following reference when using TractoR in your work:
J.D. Clayden, S. Muñoz Maniega, A.J. Storkey, M.D. King, M.E. Bastin & C.A. Clark (2011). TractoR: Magnetic resonance imaging and tractography with R. Journal of Statistical Software 44(8):1-18. tools:::Rd_expr_doi("10.18637/jss.v044.i08").
crossprod
for the matrix cross product.