并行矩阵乘法

Question

我写了一个简单的并行矩阵乘法，使用par和pseq。

运行此程序后，未转换任何火花（SPARKS：20（0转换，0修剪））。

我想听听您对改善此计划的评论。

另外关于在Haskell中学习并行编程的方法。

import Data.List 
import Control.Parallel 

parHelp :: (Num a) => [ a ] -> [ a ] -> a 
parHelp [] [] = 0 
parHelp (x : xs) (y : ys) = ret where 
ret = par a (pseq b (a + b)) where 
     a = x * y 
     b = parHelp xs ys 

helpMult :: (Num a) => [ a ] -> [ [ a ] ] -> [ a ] 
helpMult _ [] = [] 
helpMult x (y : ys) = ret where 
ret = par a (pseq b (a : b)) where 
    a = sum . zipWith (*) x $ y 
    b = helpMult x ys 

mult :: (Num a) => [ [ a ] ] -> [ [ a ] ] -> [ [ a ] ] 
mult [] _ = [] 
mult (x : xs) ys = ret where 
ret = par a (pseq b (a : b)) where 
    a = helpMult x ys 
    b = mult xs ys 

main = print $ mult [[1 .. 4 ] , [ 1 .. 4 ] , [ 1 .. 4 ] , [ 1 .. 4] ] (transpose [[1 .. 4 ] , [ 1 .. 4 ] , [ 1 .. 4 ] , [ 1 .. 4] ]) 

Answer 1

您是否尝试过非常大的（至少1000x1000）矩阵？计算太短而无法平行。