To put this another way, (x = y) compares atoms and will produce an
array if applied to an array (and will give length error if applied to
arrays that don't agree). (x -: y) answers the question 'are these
things the same?' and returns 0 or 1.
In if.-statements, you usually want -:
if. x = y do.
...
end.
Only the first atom of the result of (x = y) is tested.
It is not true that ,0 and 0 are treated the same. That is an illusion
fostered by the fact that leading axes of 1 have no effect on display.
Play with
z =: 0
az =: ,0
and see the differences between
z + az and z + az
z +/ az and z +/ z and az +/ az
You might want to use dissect to display the shapes, which is how these
results differ.
Henry Rich
On 12/20/2017 2:04 AM, Raul Miller wrote:
Or, more specifically, = is comparing atoms (the things that go into
arrays, which includes everything in a box - including the shape of
things in the box).
Thanks,
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