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comment Real and Imaginary parts of solutions to a complex linear ODE system
Is there an issue with getting the solution and then using Re and Im to separate the real and imaginary parts? May be coupled with the use of ComplexExpand? A full MWE also helps.
Aug
31
comment Dsolve implicit solution to a Differential Equation
can you show an example of what you mean? That will take all the guessing out. A picture is worth 1,000 words.
Aug
29
comment Volume enclosed by two surfaces of revolution
You do not need to integrate or differentiate to plot an expression, Just use the Plot command. f1 = Pi^2 Sin[x] (Cos[x]^3); f2 = 4 x^2; Plot[f1, {x, -2 Pi, 2 Pi}] Plot[f2, {x, -2 Pi, 2 Pi}] I get this: !Mathematica graphics
Aug
29
comment After editing a file Mathematica 10 interprets […]^2 as […(])^2
I can't reproduce it. V10 on windows. Screen shot. !Mathematica graphics may be you have some hidden char inserted by mistake. If you post the notebook somewhere may be someone can better help you.
Aug
28
comment InterplationOrder, ListPlot3D and using AbsoluteOption to find value used. Slow using InterpolationOrder
I see. So none of options such as PlotStyle used can be queried using AbsoluteOptions. Just tried it on normal plot: p0 = Plot[Sin[x], {x, -1, 1}, PlotStyle -> Red]; AbsoluteOptions[p0, PlotStyle] and this also gave an error. This makes AbsoluteOptions not as useful as I thought before. May be this is what the book means by "special options" in the screen shot I posted. Thanks.
Aug
28
comment InterplationOrder, ListPlot3D and using AbsoluteOption to find value used. Slow using InterpolationOrder
@Mr.Wizard Yes, but this is one part of it. The other part is why I get an error when query this option? I did not want to split this to 2 questions. But may be I should have. What do you think? Should they be separate? I can do that. ps. the slow down is really large as can be seen by the numbers. A bit of slow down ok, but 10 times slower?
Aug
28
comment The correct pattern for Cases
nice. May be you explain a little for us newbies how this works :)
Aug
25
comment implement the ZOH in mathematica
@NatanBravoG. There is an option that allows you to bypass stateSpaceConversion. I've updated my answer for your example above.
Aug
23
comment Error when using EquationTrekker
on version 10, windows 7, it hanged. But I saw message Message text not found -- (PropertyValue[{canvas ,canvasPane ,All},Name->trekPane ]) (1) >> show up before it hanged
Aug
21
comment How to combine one or more rotated graphics objects?
Would'nt be easier to just change the order of Graphics and Rotate? Like this: e1 = Graphics[Rotate[{Blue, Opacity[.75], Disk[{0, 0}, {1/3, 1/4}]}, \[Pi]/3]]; e2 = Graphics[Rotate[{Red, Opacity[.75], Disk[{0, 0}, {1/3, 1/4}]}, \[Pi]/7]]; Show[{e1, e2}] !Mathematica graphics
Jul
22
comment Is there a list of Octave functions mapped to the related Mathematica one?
there are lots of problems solved by Matlab and Mathematica side-by-side here
Jul
22
comment How to convert \[Formal…] symbols to standard ones in an expression?
yes. These are solutions from a set of differential equations that I am processing. So it will really include x and y as these are the same symbols used for each equation. It is just that M sometimes returns solutions using \Formal which causes problem for Latex. I am not using the solution for anything other than converting it to Latex.
Jul
22
comment How to convert \[Formal…] symbols to standard ones in an expression?
Thanks, yes, that is good. no unicode. It is not critical that x and y are being replaced by a and b. (x,y just happened to be more common to use) but will live with this solution. thank you
Jul
22
comment How to convert \[Formal…] symbols to standard ones in an expression?
The generated code (from TeXForm) still contain those trouble invalid code) which are the \unicode. When I do TeXForm[%] on the result from your code, it still shows up with invlaid latex code that uses \unicode. The main reason I wanted to remove those \Formal and replace them with normal symbols is to avoid this unicode being generated. I'll update the question to make it more clear. You have removed all the other unicode, good, but one is still there. !Mathematica graphics
Jul
22
comment HoldForm doesn't hold form
comparing the difference in ??Plot between V9 and V10, I noticed only difference is PlotTheme:> was added to V10. I do not know if this has anything to do with this change of behavior or not. This change might break existing code which used HoldForm in labels.
Jul
20
comment How to enter chemical equations?
I would use Latex. tex.stackexchange.com/questions/142865/… . Use the right tool for the right job.
Jul
20
comment How to make Mathematica save all open files, or automatically ask to save each file when closing
I just found out, this is not the behavior I wanted at all. This has caused me problems. There are times I make a change to the notebook, but then decide I do not want the cnahges, and close the notebook without saving by clicking on "X" corner of the window. It turns out Mathematica now still saves the changes I made ! as it never asks me if I want to save it first as it used to before. This is not what I wanted. I wanted it to ask me if I want to save the changes. So I have rolled out this option back to the way it was. AutoSave is not what I want actually.
Jul
20
comment How to make use of Associations?
Is there any advantage to doing AppendTo[pinfoIm, "lastName" -> "Brezhnev"] vs. pinfoIm["lastName"] = "Brezhnev"? thanks.
Jul
20
comment Invert 3D objects (shape) to 3D patterns objects (shape)?
what exactly do you mean by negative model ? and what is the pattern object?
Jul
19
comment Interactively Manipulate SparseArrays or Lists
{params[c], 0, 50} here param[c] is not a control variable. This sould be a symbol, like x, c, y, etc.. not a function.