multiply two vectors - I want a scalar but I get a vector?

Question

This is my code:

a <-c(1,2,3)
b <-t(a)
print(a*b)

I would expect the result to be 14, since a column vector multiplied with a row vector with fitting dimensions should be a skalar.

However, I get:

print (a*t(a))

 [,1] [,2] [,3]

[1,]    1    4    9

Hence the partial sums instead of the whole sum. How can I fix this?

Answer 1

If what you essentially want is the sum of the products, then all you need is sum(a*a)