dopar.nn=T memory error

[brett-mckinney]

For large data, npdr runs out of memory when dopar.nn=T (parallel nearest-neighbor calculation). Temporary fix is dopar.nn=F. A long-term solution may be to use big.matrix from the bigmemory library to enforce a shared-memory version of the distance matrix instead of allowing copies of the matrix to be exported to the workers.

https://stackoverflow.com/questions/31575585/shared-memory-in-parallel-foreach-in-r