r - sum of the quadratic difference between two variables -

how can calculate sum of quadratic difference in gnu r between 2 variables considering following random data?

set.seed(100)  <- sample(1:100, 10) b <- sample(100:1, 10) 

i have not found it.

i'm not sure phrase "sum quadratic difference" means since both "-" , "^" functions vectorized, can get:

> (a-b)^2  [1]   49  169  324 3136  324   81   16 1024 1849  225 

so if working residuals might "say":

> sum( resid <- (a-b)^2 ) [1] 7197 > resid  [1]   49  169  324 3136  324   81   16 1024 1849  225 

if instead means summing differences of squares might use:

> sum( resid <- a^2 - b^2 ) [1] -5149