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Nov
15
comment How to programmatically extract mathematical formulas from Word with Mathematica 9?
This answer includes some C# code for converting OMML to MathML. It might be some help.
Nov
15
comment How can I Integrate large trigonometric expressions more efficiently?
You need to supply a couple of examples of the integrations, otherwise we don't know why it's so slow.
Nov
11
comment Distribution of block maxima of gaussian random variables
You need to use ExtremeValueDistribution for maxima, GumbelDistribution is for minima. This is explained in the documentation for GumbelDistribution
Nov
11
comment Glitch in Filling?
Bug report now sent
Nov
10
comment Opacity function applied to Graphics Objects
Looks right to me.
Nov
10
comment Opacity function applied to Graphics Objects
I think Texture is the way to go, but for an opacity gradient the gaussian should be in the alpha channel.
Nov
9
comment Hermite method in Mathematica
A misunderstanding here, I think. The Hermite method is what the InterpolatingFunction is using (see here), not the method used by NDSolve.
Nov
9
comment Opacity renders lines incorrect in certain viewing angles
Looks like an issue with hardware rendering then, I suggest you submit a bug report to Wolfram.
Nov
9
comment Opacity renders lines incorrect in certain viewing angles
I suspect a problem with the hardware rendering engine. Does this help? Style[%, "RenderingOptions" -> {"Graphics3DRenderingEngine" -> "BSPTree"}]
Nov
8
comment TrigExpand Idiosyncracies
I assume that somewhere inside TrigExpand the pattern Sin[_]^2 f_[_] leads to different transformation rules according to whether f is a trig function or not. You have simply found a case where one of those transformations gives a result which a human mathematician would discard as inelegant.
Nov
7
comment Matrix multiplication
Yes I figured the question was more about the memory usage than the specific example, that's why I posted a comment instead of an answer. All I can really say about the speed is that I know that Dot is super-optimised for packed arrays, far far quicker than the equivalent number of arithmetic operations. I expect @ybeltukov or @Szabolcs could give a more knowledgeable explanation.
Nov
7
comment draw part of parabola using graphics
@user2485710, Fit does least-squares fitting. There will be plenty of curve fitting libraries for C if you google it. For this specific case it's overkill in fact, because there is an exact solution for the quadratic passing through 3 points. I just used Fit because it's quick and easy to do it that way in Mathematica.
Nov
7
comment Matrix multiplication
Try this instead w = First@Transpose[v]; f = Array[Cos[#1 #2] &, {dim, dim}]; u = Transpose[w].f.w; result = u + Transpose[u];
Nov
7
comment draw part of parabola using graphics
@ubpdqn, I wouldn't worry about it. Ugly code that works is still code that works :-)
Nov
7
comment Matrix multiplication
It seems to me that t = Total[v]; u = Transpose[t].t; result = u + Transpose[u]; will give the same result in a fraction of the time.
Nov
7
comment Glitch in Filling?
Seems to be related to the last point of the first line being lower than the second to last point of the second curve. Try this Manipulate[ ListLinePlot[{{10, 10, a}, {b, b, 0}, {0, 0}}, Filling -> {1 -> {{2}, Brown}, 2 -> {{3}, Gray}}, PlotRange -> {{1, 3}, {0, 11}}], {{a, 7}, 0, 10}, {{b, 5}, 1, 9}]
Nov
2
comment Negative Infinity limit
As Sjoerd says, the expressions are not equivalent. You have mapped x to Exp[x] and then also multiplied by Exp[x]. Voting to close as a trivial error.
Nov
2
comment Integrating elements from matrix
It's great that you included your code, but please add more description about what you are trying to do. It's hard to understand an algorithm by looking at code which fails to implement it.
Oct
31
comment Why does the documentation call functions “pure”?
@Nasser, I think your comment would make a good answer.
Oct
30
comment Using FindFit to return a list of possible best fits
A single example of the generic class would be better than nothing! Without one, anyone wanting to help you must first invent a function and some data which exhibits this issue with FindFit. People are less likely to tackle your problem if they have to invest extra time just to get started.