Issues with zeros et al functions of array contexts

[inducer]

• Decide between actx.np.zeros and actx.zeros.
• zeros_like doesn't currently retain metadata from its argument, resulting in lazy compile issues.

cc @majosm @MTCam @kaushikcfd

[alexfikl]

actx.zeros doesn't work on containers (like all the other methods in actx), so they're not quite equivalent. Should it?

[inducer]

I don't see why it shouldn't. actx.freeze is (legitimately) growing container support (#158).

[alexfikl]

Did some of this work in #178:

• actx.zeros_like and actx.empty_like work on containers.
• at least the eager pyopencl version propagates tags in both of those.

actx.zeros and actx.empty can't really get support for array containers, since they don't have a template to mimic. Also, there's no actx.np.zeros, so that should be done as well!

[inducer]

Thanks for working on that!