如何使用 MapReduce 在 python 中乘以矩阵？

Question

假设我有两个 2X2 矩阵，如下所示。

A,0,0,1

A,0,1,0

A,1,0,0

A,1,1,1

B,0,0,2

B,0,1,3

B,1,0,4

B,1,1,5

例如B,1,0,4，表示矩阵 B，第 1 行，第 0 列，值 4。

如何使用 MapReduce 方法计算两个指标的乘积以获得此输出：

0,0,2

0,1,3

1,0,4

1,1,5

Answer 1

我制作了一个cache.txt文件来输入矩阵的尺寸。(row_a, col_b, col_a)input.txt包含矩阵。代码如下。cache_info = open("cache.txt").readlines()[0].split(",")row_a, col_b, col_a = map(int, cache_info)mapperOutput = open("mapperOutput.txt", "w")for line in open("input.txt"):    matrix_index, row, col, value = line.rstrip().split(",")    if matrix_index == "A":        for i in range(0, col_b):            key = row + "," + str(i)            mapperOutput.write("%s\t%s\t%s" % (key, col, value) + "\n")    else:        for j in range(0, row_a):            key = str(j) + "," + col            mapperOutput.write("%s\t%s\t%s" % (key, row, value) + "\n")mapperOutput.close()numbers1 = list()for line in open("mapperOutput.txt"):    curr_index, index, value = line.rstrip().split("\t")    index, value = map(int, [index, value])    numbers1.append((curr_index, index, value))numbers2 = numbers1initValue1 = list()initValue2 = list()for i in numbers1:    checker = 0    for j in numbers2:        if i == j:            if checker == 0:                checker += 1                continue        if i[0] == j[0]:            if i[1] == j[1]:                initValue1.append([i[0],str(i[1]),i[2]*j[2]])initValue2 = initValue1myOut = dict()counter = 0for i in initValue1:    if counter > (row_a*col_b*col_a):        break    if i[0] in myOut.keys():        counter += 1        continue    counter += 1    myOut[i[0]] = i[2]    inercounter = 0    for j in initValue2:        if i[0] == j[0]:            if i[1] != j[1]:                inercounter += 1                if inercounter > col_b - 1:                    continue                myOut[i[0]] += j[2]for key,value in myOut.items():    print(key,value)输出将是：0,0 20,1 31,0 41,1 5