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Jul
11
comment ParametricPlot - Problem with ColorFunction
I meant the tendency of some people to start accusing everyone who comments "Are you the downvoter?" "Are you the downvoter?". Often if someone reveals that they downvoted, the OP then goes and downvotes or leaves negative comments on their other unrelated posts. I'm not suggesting you would do that, I'm simply saying that one should not be expected to reveal one's votes, and asking whether one has downvoted should be considered an intrusive question.
Jul
11
comment ParametricPlot - Problem with ColorFunction
If you don't care then why call them a coward and ask for a reason?
Jul
11
comment ParametricPlot - Problem with ColorFunction
ColorFunction -> (ColorData["DarkRainbow"][Abs[2 #3 - 1]] &)
Jul
11
comment Neural Network and New Mathematica version
Summary of New Features in Mathematica 10, Ctrl+F "neural", no results. However, it does have a whole bunch of new machine learning functionality, so if you're not married to neural networks per se this might be useful.
Jul
11
comment complicated color function (no rescale)
StackExchange is not the same thing as a discussion forum; please read the about page and how to accept an answer.
Jul
11
revised Rough mesh lines in partially opaque 3D plots
edited title to remove ambiguity: is it the mesh lines or the plot that is partially opaque?
Jul
11
comment Rough mesh lines in partially opaque 3D plots
Works fine for me on Mathematica 9.0.1 on Mac. What's your version and platform?
Jul
10
comment Random numbers that sum up to specific value
+1: This is the approach endorsed by whuber and the statistics StackExchange. It also runs in only $O(n\log n)$ time.
Jul
10
comment Can mathematica rearrange an equation and solve/plot it?
You can also try ContourPlot3D[Sin[x + y + z] == x^2 y - z, {x, -5, 5}, {y, 0, 1}, {z, 0, 1}, ViewPoint -> {Infinity, 0, 0}, MeshFunctions -> {#1 &}, Mesh -> 20, ContourStyle -> None, Ticks -> {None, Automatic, Automatic}, AxesLabel -> {"", y, z}]
Jul
9
comment How can the opacity of a dense data set be automatically chosen?
That's pretty cool! I wonder what happens if you have two different datasets in the same plot -- are their point sizes adapted independently or are they the same? I can see arguments in favour of either.
Jul
9
comment Limits explanation in doc
Think of it as the direction you're going, not the direction you're coming from. (Although I do agree with you that it is a little inconsistent with the traditional mathematical notation. Perhaps they should have just used Above and Below for no chance of confusion.)
Jul
8
comment Implicitly differentiate an equation, then solve the resulting equation
Funny, this gives Indeterminate for f = x + y and 1 for f = x + y + z, both of which are incorrect.
Jul
8
comment Horizontal shift in fitting data by a sinusoidal nonlinear model
It helps to provide reasonable initial guesses for the parameters so that the solver is more likely to converge to the right answer. In your case, it makes sense to start b at $\pi/180$ and d at the mean of the data: NonlinearModelFit[data, d + a Sin[b (x - c)], {a, {b, π/180}, c, {d, Mean@data[[All, 2]]}}, x]["BestFit"]; this gives the desired fit.
Jul
8
answered Problem regarding 3D plot of a Moebius strip from a set of 2D points
Jul
8
comment Identifying the color in Image
Simpler way to preserve the structure: Map[PixelValue[#, .5*ImageDimensions@#] &, p, {2}]
Jul
8
answered Why Plot3D does not accept Epilog option
Jul
8
comment Defining the Moyal Product in Mathematica
Thanks for clearing that up! I for one am perfectly happy to take your word for it.
Jul
8
comment Defining the Moyal Product in Mathematica
Sorry, by "final test" I meant the final one of your "Here are some tests" block, namely star[x^6 p^2, p^7 x^4]. I also should have mentioned that I took the sum up to 100 terms and the result didn't change, so I assumed that it had converged. As you stated, for any two polynomials the series will reduce to a finite sum, and that is what the above result seems to be.
Jul
8
comment Defining the Moyal Product in Mathematica
Your final test doesn't match the result I get with @belisarius's code in the comments: 9525600 h^8 p x^2 - 5556600 I h^7 p^2 x^3 - 396900 h^6 p^3 x^4 - 132300 I h^5 p^4 x^5 - 20160 h^4 p^5 x^6 + 252 I h^3 p^6 x^7 - 153 h^2 p^7 x^8 + 17 I h p^8 x^9 + p^9 x^10. The last two terms agree but the others don't. I don't know which result is correct.
Jul
8
comment Defining the Moyal Product in Mathematica
There's also the fact that with your current definition you'd have to call Star[Function[{x, p}, x], Function[{x, p}, p]] instead of Star[x, p].