Random error with Partition?

Questions
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1

Dear All,

I’ve been getting ‘random’ errors from Partition, which (after re-starting kernel, or even just re-evaluating) do not pop up).

ScreenShot2016-08-23at15.07.40.png
ScreenShot2016-08-23at15.07.40.png1378×322 26.9 KB

If I do the stack-trace you get the last lines, you see 4 coordinates, which should be partitioned cyclically. Which works just fine, but sometimes spawns an error, seemingly randomly.

Restart/reevaluation generally solves it…

Any advice?

2

Hi Sander,

I cannot reproduce this. (MMA 11.0.0, OSX 10.11.6)

Cheers,

Marco

3

Hi @Marco Thiel

I have attached a Notebook. This is a copy from the stack-trace. If I execute the top cell (in 11 or 10.4.1, both mac) it does not work.
The second cell also does not work.

If I copy cell 2, and retype Det /@ it does work…

Could you verify this?

4

Is this due to some Hold operation that goes away?

5

I do see that, too. It is unexpected indeed.

Cheers,

M.

6

Dear Sander,

I have used Ctrl+Shift+E in the second and third cells and found that they are not identical. The second cell contains an additional TagBox[]

weird.png
weird.png1205×678 158 KB

Is this the problem?

7

I think the cells of the stack are in HoldForm, but the last one I copied manually, but only partially, then you don’t copy the Hold around it, just the contents. But I still don’t understand why the Partition would trip… (this was a side-‘observation’)…

Thanks!

8

TagBox does effect evaluation if placed improperly

holdform i didn’t analyse but that could effect evaluation and isn’t part of normal output

hacked i assume