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Dec
4
comment Inverse of LogIntegral
FWIW the inverse function breaks for integers greater than 3824273 and for reals greater than about 261001. Just some implementation limits I suppose.
Dec
4
comment How to export a Graphics to PNG with BitDepth greater than 8?
... playing with some more.. you need to be careful, in some cases you get a nominally 16bit file (reported by BitDepth) but if you look at the ImageData you see only 256 unique values. for some reason you need to specify ImageSize ie Export["test16.png", Image[gr, "Bit16"], ImageSize -> 1000] to get true 16 bit output.
Dec
4
comment How to export a Graphics to PNG with BitDepth greater than 8?
+1 I can confirm this works. Note that the combination of "Bit16" with a graphics argument isn't documented so this isn't quite obvious. By the way the options "Real32" and "Real" lead to 16 bit output as well.
Dec
3
comment Table operation after export and import of data does not give me the same result
its basically the same, go ahead and accept the existing answer..
Dec
3
answered Regular Expression - for html objects
Dec
3
comment Table operation after export and import of data does not give me the same result
If you just want to save/retrive the data use "m" or "mx" format, eq Export["data.m",m1] these are "native" mathematica formats and will safely preserve whatever expression you export. If you really want to use the "Data" format for some reason that will take a bit of work to read it back in (clarify if that's what you need.. )
Dec
3
comment How to evaluate the same code in a whole bunch of existing notebooks
Have you tried working with NotebookEvaluate ? I'd suggest you take a stab at it and see what problems you run into.
Dec
2
comment Should “counters” used in Do, Table, … within Module be declared as local?
for entertainment ask a "c" programmer what this does.. i = {4, 5}; Do[Do[ Print[ i ] , {i, i}], {i, i}]
Dec
2
answered Eigenvectors of large symbolic matrix
Dec
2
comment Eigenvectors of large symbolic matrix
I should say I have 32GB ram. (dual core xeon / windows ) I'd guess this is a memory intensive procedure and the time will go way up if you are disc swapping. Factoring the j didn't make much difference for me, by the way.
Dec
2
comment Eigenvectors of large symbolic matrix
Eigenvectors returns a result in 15 seconds for me.
Dec
2
comment Visually differentiating arguments of If
I wonder is there a clean want to change the symbols? Especially on my linux system the semicolon and comma are very hard to distinguish.
Dec
2
answered Visually differentiating arguments of If
Dec
1
answered Noninteger indices for tables
Nov
26
comment Function to calculate finite difference
the correct expressioms are easy enough to find en.m.wikipedia.org/wiki/Finite_difference if you just want to validate. you of course need to divide by the deltas.
Nov
25
answered Custom list plot ticks
Nov
25
comment Deferent results depending on the input form of the matrix
The other issue to note in the docs is this : "For approximate numerical matrices m, the eigenvectors are normalized."
Nov
24
revised Cumulative histogram with log-log scale
added 508 characters in body
Nov
24
comment Cumulative histogram with log-log scale
+1 now I feel silly for doing it the hard way..
Nov
24
revised Cumulative histogram with log-log scale
added 144 characters in body