Implementing Sparse Vectors With Associative Arrays/Compiler Bug?

[jerro]

> Are errors of this magnitude to be expected using doubles, or 
> is this a compiler bug?

Errors of this magnitude are to be expected. the value of accum 
in your example is somewhere around 3e+08, so the relative error 
is around 1e-15, and double.epsilon is 2.22045e-16.

By the way, you can use unpredictableSeed to get an unpredictable 
seed.