# Apply functions to a nested list in parallel?

Posted 6 months ago
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 Hi. I have a function that generates a nested list containing coordinates, now i want to apply a function to those coordinates.  'CoordinatesGeneration = Function[ {m, n, a, b}, Table[Table[{a /2 (i + j), a (j - i), b /2 (k + h), b (k - h)}, {i, -(1/2) (m - 1), (m - 1)/ 2}, {j, -(1/2) (m - 1), (m - 1)/2}], {h, -(1/2) (n - 1), (n - 1)/2}, {k, -(1/2) (n - 1), (n - 1)/2}]];' What i tried is to flatten the list and then use partition to group the list each 4 elements and then use apply. Apply[f ,Partition[Flatten[PositionGeneration[10, 10, a, b]], 4], {1}]]] It worked, but now i want to do the evaluation in parallel. I try to use ParallelMap with Apply inside and ParallelCombine but it only work if the list was less than 4 groups in 5 groups it doesnt do what i wanted. ParallelCombine[ f @@@ # &, Partition[Flatten[PositionGeneration[3, 3, a, b]], 4], Plus] I want to parallelize it because when i have big numbers in counters m,n the evalution can take several seconds, so maybe using parallel functions can speed up a bit.Thank you.
 Map can operate at low levels in a list In[2]:= Map[f, {{a, b}, {c, d, e}}, {2}] Out[2]= {{f[a], f[b]}, {f[c], f[d], f[e]}}