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,0,0,1A,0,1,0A,1,0,0A,1,1,1B,0,0,2B,0,1,3B,1,0,4B,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：0,0,20,1,31,0,41,1,5

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 = numbers1

initValue1 = 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 = initValue1

myOut = dict()

counter = 0

for 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 2

0,1 3

1,0 4

1,1 5