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1d
answered Colorize an image using two parameters
1d
comment Speed up calculation
@belisarius, the pixels injected into OP's superImg increase in value as the image list is stepped through. So the final value in any pixel is always the maximum.
1d
answered Speed up calculation
2d
awarded  Enlightened
2d
awarded  Nice Answer
2d
comment Better answer to Santa's riddle about sum of a number's divisors?
@Apo, x matches a Sequence in that pattern, so Times[1, x] splices the sequence into Times, ie it gives the product of the elements in x. It's a nice trick when you're playing golf but probably best avoided in code that you might want to read again one day...
2d
comment My code does not give the same results on mathematica 9 and 10
I get the same as @Kuba - no difference between versions 9 and 10.
Dec
15
revised Processing a circular rainbow in an image
added 279 characters in body
Dec
15
answered Processing a circular rainbow in an image
Dec
15
revised CUDALink Error: A CUDALink kernel timed out?
Expanded answer to include a link to the documentation and a bit more information
Dec
15
comment CUDA paclet and Mathematica 10.0.2 code problem
It's working okay for me with paclet version 10.0.0.1 on Windows 7. What C compiler are you using?
Dec
15
comment Simple image processing very slow
For finding the positions this should be quite fast: SparseArray[UnitStep[imgData - 50]]["NonzeroPositions"]
Dec
15
answered ReplaceImageValue and ReplacePixelValue extremely slow
Dec
13
comment about the design of Part related to Association
With your last question you are misunderstanding the effect of Span. It returns the selected parts wrapped in their original head. So you only get a List back if you are extracting parts from a List. For example f[1, 2, 3][[1;;2]] gives f[1, 2] not {1, 2}.
Dec
13
comment about the design of Part related to Association
@matheorem, it looks like there is still some work to do with pattern matching on Associations, but I wouldn't expect the behaviour with Part to change.
Dec
13
comment about the design of Part related to Association
@matheorem, there's some discussion of that here. I don't claim to fully understand the situation, but I have found that associations mostly make sense if you regard the values as being what's really there at level 1, and the keys as ephemeral magic labels which are transparent to most operations and which vanish as soon as the value is no longer contained inside an association.
Dec
13
comment about the design of Part related to Association
@matheorem, because the value is not the rule "a"->1, it is just 1. Note that FreeQ[<|"a"->1|>, Rule] is True - there is no Rule in that expression, despite appearances.
Dec
13
comment ListContourPlot interpolation fails if x and y axes have different scales
It used to be possible to use Method -> {"DelaunayDomainScaling" -> True} in the contour plot to work around this issue. Unfortunately it doesn't seem to work in version 10.
Dec
13
comment about the design of Part related to Association
I agree, the behaviour of Part with Association is consistent and expected.
Dec
12
answered Better answer to Santa's riddle about sum of a number's divisors?