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Aug
21
comment How to find numerically all roots of a function in a given range?
Very interesting! You got a mix-up in the naming: comrade should be colleague in the expression for rts. Actually, maybe one should call it companion.
Aug
21
comment Lens profile in a grid
I'm voting to close this question as off-topic because it's asking to fix code that's based on incorrect relations.
Aug
20
comment Lens profile in a grid
As @xzczd mentions, your starting equations are incorrect. Specifically, you're missing one of the in-plane magnetic field components that arise when the electric field is allowed to depend on x and y. Do you really need to use this low-level approach, or are you also interested in higher-level solutions using NDSolve? You may also want to look into RotateRight and RotateLeft.
Aug
19
comment Getting Boston Marathon Data
Perhaps you can add details of what you have already done manually, if you think it can be automated.
Aug
19
comment Getting Boston Marathon Data
If there's no public API for automated requests, this is basically a question about hacking their form submission interface to scrape the data. Therefore, the main issue is really quite unrelated to Mathematica. Have you tried anything?
Aug
18
comment Symmetrise a complicated expression
For non-polynomials, you can always use the method in my answer to What is the command to find function invariant?. But you seem to be looking for some kind of "visual" symmetry. This should be defined more clearly, I think.
Aug
18
comment Symmetrise a complicated expression
What would you do with an expression like Abs[Log[a/b]? I don't think the problem is well-defined in this form.
Aug
18
comment Can't get rid of vertical background color
I don't see this on Mac. It looks like this is an operating-system dependent bug. Are you using Linux?
Aug
17
comment Shadowing issue with DeleteDuplicatesBy
Have you tried a simpler test such as DeleteDuplicatesBy[{{a,y},{b,y},{c,z},{d,y}},Last] before doing the more complicated example in your screen shot? Or is there a reason you posted the more complicated example? Maybe it would also help to know your OS.
Aug
17
comment How to increase font size in front-end UI Menus
Help windows are notebooks, different from the menus you mention. So the answer to @MarcoB s question is quite important for a useful answer.
Aug
17
comment Using Padding with Text and Style
Yes to both. E.g., try Graphics3D[myText["{1,0,0}",{0,0,0},Padding->20,Background->Directive[Opacity[.‌​5],Red]],Background->LightBlue]. Or SetOptions[myText,Background->LightOrange].
Aug
17
comment Using Padding with Text and Style
Sure, your best bet is to define a function. I'll add that...
Aug
15
comment How to export graphics for Blend4Web
Another possible dupe: or How to export .mtl files for 3D textured objects. These are duplicates because they come to the same conclusion that textures aren't exported. In my answer here, I do get colored rendering but only because I exported the light sources that created the colors. No textures.
Aug
14
comment FindInstance returns Indeterminate in version 9, but not in 8
@MichaelE2 Oh, I wasn't aware of that, or maybe forgot. It's OK - I'll remove the tag again. Too bad we don't have a real bug tracker.
Aug
14
comment Visualize transformation used in multiple integration
In addition to @Guesswhoitis. suggestion, it could be fun to illustrate things with ImageTransformation. E.g., if you take an image with a regular pattern on it, then the transformation will also help explain the change in density that corresponds to the Jacobi determinant.
Aug
14
comment ErrorListLogLogPlot and PlotMarkers
Reference for the package is in this Q&A.
Aug
13
comment Convert DE to first order?
@SubaThomas I think I fixed the copying problems in the question, so it should be possible to use the actual equations in our answers now.
Aug
13
comment Convert DE to first order?
@SubaThomas That's probably what the question is after - but I don't know for sure if there's something wrong with applying NonlinearStateSpaceModel to the OP's equations, so if that's the case my pedestrian approach could be a work-around.
Aug
13
comment Convert DE to first order?
In addition to @SubaThomas advice, please also specify in what way the documentation didn't help.
Aug
13
comment Convert DE to first order?
The code isn't copyable as a valid Mathematica expression.