A few questions

[gthayyil]

Hey Michael,
I was wondering if you could answer a few questions I had.

1. How a slice works when using it with extract Matrix, and what its parameters refer to?
2. What def(wait(self)) is and when or how it might be useful?
3. Is there a difference between creating an array from 1 to n, and creating a vector using def_1_to_n(n) and using operations on them with matricies?

Thanks a lot,
Georgy Thayyil

[michelp]

Hi Georgy,

Slicing is similar to how it's done in numpy with square brackets []. A[0] will "slice" the zeroth row. This works for extraction and assignment. This is the same as A[0,:]. You can slice "all" of a matrix, which is similar to copying it A[:,:]. Ranges can also be used with slices A[1:3,3:4] will slice the rows 1 and 2, and column 3. In python the colon is a syntax for a slice object:

https://docs.python.org/3/library/functions.html#slice

wait() is used for multithreaded programs where threads may touch the same object. you probably won't need it, see the suitesparse user guide for the details if interested.

Vector.from_1_to_n creates creates the vector and fills it with integers. It's in LAGraph I'm not sure why I included it I haven't actually used it. Give it a try in the interpreter it's one of the many ays to make objects.

[gthayyil]

Thanks a lot, this definitely helps me better understand pygraphblas.