I have a "sparse array" like this
arr[1.5]=0.4, arr[3.5]=0.7, arr=0.3
which is not really a sparse array since the keys are not all integers. This is like a hash table or associative array.
How can I convert
arr into a list? I tried
Normal[arr], but it won't work.
I would like to be able to compute
Total@arr, but first it needs to be converted to a normal list.