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7h
comment Plot of Implicit Equations
I think you've misunderstood the plot. As your first plot shows, $f$ has a very large number of zero crossings in the solid region. Therefore, ideally a very large number of contours should be drawn there. If you draw a very large number of contours in a small area, it looks like a solid region, as the red plot correctly shows. It's the Mathematica plot which incorrectly suggests that, for example, there are no zero crossings in the neighbourhood of $(4,2)$.
9h
revised Plot of Implicit Equations
added example
1d
comment How can I use ContourPlot to creat streamline for a free surface domian: proper arrow orientation and correct domain?
Anyway, I do think that this is a misfeature of Mathematica. Contour lines of a scalar function can be assigned a consistent orientation based on which side of the line has the larger function value, and it would be nice if Mathematica automatically respected that orientation. In the meantime, I hope someone posts a nice workaround.
1d
comment How can I use ContourPlot to creat streamline for a free surface domian: proper arrow orientation and correct domain?
Here's a nice fake example for y'all: sl = ContourPlot[Cos[x] + 1/2 y^2, {x, -2 π, 2 π}, {y, -π, π}, Contours -> 5, AspectRatio -> Automatic, ContourStyle -> Directive[Black, Opacity[1]], ContourShading -> None]
1d
revised Is it possible to find generating functions of infinite sequences with Mathematica?
edited title
2d
answered Color Transfer from colored image into grayscale image
Dec
16
comment How can I create a minimal surface with trefoil knot as inner edge and circle as outer edge?
Although for the latter, "Visualizing Minimal Surfaces" from The Mathematica Journal seems relevant.
Dec
16
comment How can I create a minimal surface with trefoil knot as inner edge and circle as outer edge?
Topologically, this is the Seifert surface of the union of a trefoil knot and an unknot (a circle). Seifert gave an algorithm for obtaining such a surface, but converting it to Mathematica code is another matter. As is making it a minimal surface...
Dec
15
comment Processing a circular rainbow in an image
Is this answer really enhancing the colours and structure that exist in the original image, or is it simply imposing the colours and structure of a different image on it?
Dec
14
comment Sampling phase space uniformly for a given energy
...This sounds like a hard research problem. Even in your 1D example, if you don't have $\frac1{2m}=\frac{m\omega^2}2$ you're trying to sample uniformly from the boundary of an ellipse, and that's not easy.
Dec
14
comment Color Transfer from colored image into grayscale image
Could you edit that into the question instead of posting it as comments? After you paste the code, select it and use the "code" button in the toolbar (fifth from left, looks like {}) to format it correctly.
Dec
14
comment Color Transfer from colored image into grayscale image
Please show the code and results of some of the "several methods" you tried.
Dec
14
revised Color Transfer from colored image into grayscale image
added 19 characters in body
Dec
12
comment Plot with Mathematica
As Mark's comment on his answer states, the code is given in the answer source. Here it is at the bottom: math.stackexchange.com/revisions/…
Dec
12
comment Plotting: Is anyone familiar with field line command?
Try "electric field of a charged line segment" and use StreamPlot.
Dec
12
comment NMinimize tries to find the fit to paramters which are not in the objective function
You've specified the optimization variables to be {x, y}, so Mathematica is minimizing the function f[x_, y_] := fun[x]. Any point {4, y} is a local minimum of this function, and Mathematica returns an arbitrary one.
Dec
12
comment multivariate lognormal distribution in mathematica
For the benefit of people who don't know R, can you also define mathematically the quantity you're trying to compute?
Dec
5
comment View inside the room
Related: Implementing a first person view of 3D objects in a scene
Dec
5
revised Differentiating an equation
rolled back to a previous revision
Dec
4
comment How to keep window above all other apps?
I agree with Szabolcs, this is something that the window manager / operating system ought to deal with. Searching for "window always on top mac" turns up a program called Afloat that you could try.