Parallel Computing for Data Science

4.4. EXAMPLE: MATRIX MULTIPLICATION 89

we can simply print c to see the product of a and b.

4.4.4 A Closer Look at the Shared Nature of Our Data

As noted, the matrix w is not returned to the caller. Instead, it is simply

available directly as a shared variable to all parties who hold the key for

that variable.

Let’s look at that a little more closely, running our test code through the

debugger:

> debug( t e s t )

> t e s t ( c2 )

debugging in : t e s t ( c2 )

. . .

debug at MM. tex#16: mgrmakevar ( c l s , ”c ” , 6 , 6)

Browse [2] > n

debug at MM. tex#17: a [ , ] <− 1 : 1 2

Browse [2] > print ( c )

An o b j e c t o f c l ass ” b i g . matrix ”

S l o t ” a