[Numpy-discussion] random integers

[Charles R Harris]

Hi All,

I've implemented several new random integer functions in #6910
<https://github.com/numpy/numpy/pull/6910>, to wit


- np.random.random_int32
- np.random.random_int64
- np.random.random_intp

These are the minimum functions that I think we need for the numpy 1.11.0
release, most especially the random_intp function for fuzz testing the
mem_overlap functions. However, there is the question of the best way to
expose the functions. Currently, they are all separately exposed, but it
would also be possible to expose them through a new dtype argument to the
current np.random.random_integers function. Note that all all the new
functions would still be there, but they could be hidden as private
functions. Also, there is the option of adding a complete set comprising
booleans, int8, int16, and the unsigned versions. So the two, not mutually
exclusive, proposed enhancements are

- expose the new functions through a dtype argument to random_integers,
hide the other functions
- expose the new functions through a dtype argument to random_integers,
not hide the other functions
- make a complete set of random integer types

There is currently no easy way to specify the complete range, so a proposal
for that would be to generate random numbers over the full possible range
of the type if no arguments are specified. That seems like a fairly natural
extension.

Finally, there is also a proposal to allow broadcasting/element wise
selection of the range. This is the most complicated of the proposed
enhancements and I am not really in favor, but it would be good to hear
from others.

Thoughts?

Chuck

[Ralf Gommers]

Post by Charles R Harris
Hi All,
I've implemented several new random integer functions in #6910
<https://github.com/numpy/numpy/pull/6910>, to wit
- np.random.random_int32
- np.random.random_int64
- np.random.random_intp
These are the minimum functions that I think we need for the numpy 1.11.0
release, most especially the random_intp function for fuzz testing the
mem_overlap functions. However, there is the question of the best way to
expose the functions. Currently, they are all separately exposed, but it
would also be possible to expose them through a new dtype argument to the
current np.random.random_integers function. Note that all all the new
functions would still be there, but they could be hidden as private
functions. Also, there is the option of adding a complete set comprising
booleans, int8, int16, and the unsigned versions. So the two, not mutually
exclusive, proposed enhancements are
- expose the new functions through a dtype argument to
random_integers, hide the other functions

+1 for a single new keyword only and hiding the rest. There's already
random.randint and random.random_integers (keyword should be added to both
of those). That's already one function too many. Adding even more functions
would be very weird.

Post by Charles R Harris
-
- expose the new functions through a dtype argument to
random_integers, not hide the other functions
- make a complete set of random integer types
There is currently no easy way to specify the complete range, so a
proposal for that would be to generate random numbers over the full
possible range of the type if no arguments are specified. That seems like a
fairly natural extension.

I don't understand this point, low/high keywords explicitly say that they
use the full available range?

Post by Charles R Harris
Finally, there is also a proposal to allow broadcasting/element wise
selection of the range. This is the most complicated of the proposed
enhancements and I am not really in favor, but it would be good to hear
from others.

I don't see much of a use-case. Broadcasting multiple keywords together is
tricky to implement and use. So for the few users that may need this, a
small for loop + array stack should get their job done right?

Ralf