I've been working on a project for a while now that requires calculating some very large datasets, and very quickly have moved beyond anything that my meager Excel knowledge could handle. In the last few days I've started learning Python, which has helped with handling the size of data I'm dealing with, but the estimated processing time for these datasets is looking to be incredibly long (possibly a couple hundred years on my laptop).
The bottleneck here is an equation that could produce trillions or quadrillions of results, since it is calculating every combination of 6 different lists and running it through an equation that you'll see in the code. The code works just fine, as is, but is isn't feasible for larger datasets than the example I included. A real dataset would be something more like Set1S, 2S, and 3S being 50 items each, and Sets12A...being about 2500 items each (50x50 in this case. These sets always have a length equal to the square of the first 3 lists, but I'm keeping things short and simple here.).
I'm well aware that the amount of results is absolutely huge, but want to start with as large a dataset as I can, so I can see how much I can reduce the input sizes without greatly impacting the results when I plot a cumulative% histogram.
'Calculator'
import numpy as np
Set1S = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
Set2S = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
Set3S = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
Set12A = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
Set23A = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
Set13A = np.array([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15])
'Define an empty array to add results'
BlockVol = []
from itertools import product
'itertools iterates through all combinations of lists'
for i,j,k,a,b,c in product(Set1S, Set2S, Set3S, Set12A, Set23A, Set13A):
'This is the bottleneck equation, with large input datasets'
BlockVol.append((abs(i*j*k*np.sin(a)*np.sin(b)*np.sin(c))))
arr = np.array(BlockVol)
'manipulate the result list a couple ways'
BlockVol = np.cbrt(BlockVol)
BlockVol = BlockVol*12
'quick check to size of results list'
len(BlockVol)
This took me about 3 minutes or so for 11.3M results, just from eyeballing the clock.
I've learned about @njit, prange in the last day or so, but am a bit stuck in trying to translate my work into this format. I do have a desktop PC with a pretty good GPU, so I think I could speed things up by a lot. I'm well aware that the code below is a big garbage fire that doesn't do anything, but I'm hoping that I'm at least getting the point across on what I'm trying to do.
It seems that the way to go is to define a function with my 6 input lists, but i'm just not sure how to fuse the itertools product and the njit together.
import numpy as np
from itertools import product
from numba import njit, prange
@njit(parallel = True)
def BlockVolCalc(Set1S, Set2S, Set3S, Set12A, Set23A, Set13A):
numRows =Len(Set12A)
BlockVol = np.zeros(numRows)
for i,j,k,a,b,c in product(Set1S, Set2S, Set3S, Set12A, Set23A, Set13A):
BlockVol.append((abs(i*j*k*np.sin(a)*np.sin(b)*np.sin(c))))
arr = np.array(BlockVol)
BlockVol = np.cbrt(BlockVol)
BlockVol = BlockVol*12
len(BlockVol)
Any help is much appreciated, as this is all very new and overwhelming.
Thank you!