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Timeline for Table and memory efficiency

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Apr 13, 2017 at 12:55 history edited CommunityBot
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Jan 9, 2015 at 13:30 vote accept MOON
Jan 5, 2015 at 21:46 comment added Mike Honeychurch Part 2. if you have a look at the Trace of both they are quite different. To fix this With[{n = 100}, Table[i*j, {i, 1, n}, {j, 1, n}]]
Jan 5, 2015 at 16:52 comment added DumpsterDoofus @yashar: I addressed your edit. In effect, you are comparing a packed array and an "almost entirely packed" array that is packed everywhere except at the top level, and thus aren't seeing much of a difference. However, the factor of 1/3 to 1/4 compression is still there.
Jan 5, 2015 at 16:51 history edited DumpsterDoofus CC BY-SA 3.0
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Jan 5, 2015 at 16:20 comment added MOON Could you please take a look at the edited question. I added the code for making a table of matrices.
Jan 5, 2015 at 16:09 history edited DumpsterDoofus CC BY-SA 3.0
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Jan 5, 2015 at 16:09 comment added DumpsterDoofus @yashar: I can't reproduce your result. ByteCount[Table[i*j*k, {i, 100}, {j, 100}, {k, 100}]] ByteCount[Table[Table[Table[i*j*k, {i, 100}], {j, 100}], {k, 100}]] gives 8000160 and 25050496. However, I was wrong about the packing ratio, it's more like 1/3 of the size, not 1/4.
Jan 5, 2015 at 15:29 comment added MOON Is this always true that packed array are 1/4 of unpacked ones? If I make a table of matrices, there isn't that much difference between packed ones and unpacked ones.
Jan 5, 2015 at 15:16 history edited DumpsterDoofus CC BY-SA 3.0
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Jan 5, 2015 at 15:12 comment added MOON I was wrong, it gets packed. I just restarted MMA and did it again.
Jan 5, 2015 at 15:10 comment added DumpsterDoofus @yashar: See my edit just now. In my case it does get packed. Could you share the code you used?
Jan 5, 2015 at 15:09 comment added MOON If I use Developer`ToPackedArray[] for the second part, it won't be packed. Isn't this command supposed to do that?
Jan 5, 2015 at 15:06 history edited DumpsterDoofus CC BY-SA 3.0
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Jan 5, 2015 at 15:00 history edited DumpsterDoofus CC BY-SA 3.0
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Jan 5, 2015 at 14:54 history answered DumpsterDoofus CC BY-SA 3.0