20,115 reputation
12768
bio website
location
age
visits member for 2 years, 7 months
seen 8 mins ago

Nov
3
comment Incorrect result from Integrate
Sure. So both Maple and Mathematica are wrong. For some reason, now I feel a little better :)
Nov
3
comment Incorrect result from Integrate
Something is wrong. I tried this on Maple, with no assumptions. Mathematica and Maple gave the same numerical answer, except Mathematica made it imaginary (with minus sign), while Maple showed it as real (with positive sign). i.e. both gave 0.37 (in absolute terms). (again, no assumptions). So either Maple or Mathematica has a bug :) here is a screen shot: !Mathematica graphics
Nov
3
comment Plotting a graph
@user10366, just play with the PlotRange. Either use All, or give specific plot range. Will add small example. See help for syntax if not sure how. Notice, I used Frame->True, so plot range syntax is a little different.
Nov
3
comment Exporting combined data plots as a PDF file
What trouble are you having? Did you use the Export command? What did you type? What error did you get? For additional information reference.wolfram.com/mathematica/howto/ExportToPDF.html and reference.wolfram.com/mathematica/ref/format/PDF.html
Nov
3
comment Find maximum from NDSolve output
Well, you can't use NDSolve if you do not have a numerical value for d and T. So, once these are set, and you get your solution xx[t] from NDSolve, then you can use many of Mathematica maximum related functions, may be NMaxValue migth do it. "gives the maximum value of f with respect to x." reference.wolfram.com/mathematica/ref/NMaxValue.html
Nov
3
comment What is the most convenient way to read definitions of in-memory symbols when we don't have the source files? (Spelunking tools)
Great stuff Leonid! would you happen to know how to use this on a Manipulate source code? When I do CodeFormatterSpelunk[ Manipulate[Plot[Sin[a x], {x, 0, 1}], {{a, 1, "a"}, 1, 10, 1}]] I just get !Mathematica graphics (I am trying to use your program to format my manipulate code, but not able to)....
Nov
2
comment How do I define an argument pattern for a Head of NOT a given value?
can't you just do f[a_Integer] := 2 a; f[a_] := 2000 a ?
Oct
31
comment Problem in exporting a plot with background to pdf
Need "backimage.jpg" also that you are importing.
Oct
31
comment How to find a specific color in one picture?
@Kuba I think that is a good answer. image = Import["1wEvU.jpg"]; PixelValuePositions[image, Blue, 0.4] gave me {{1605, 810}, {1606, 810}, {1604, 809}, {1605, 809}, ...
Oct
31
comment Solve failing and not clear why
@Amzoti sorry, copied the wrong command. It is Solve, not NSolve. I tried NSolve earlier also to see what it does. But ended up using Solve with Reals.
Oct
31
comment Avoid unnecessary truncation
Just to note, one needs "\" added before [] in the above. But this forum does not show it. So for OP, make sure to add the escape "\" like this: "*****HERE****[ThinSpace]"
Oct
31
comment Avoid unnecessary truncation
You use use the same $PrePrint command, like this: $PrePrint = AccountingForm[#, DigitBlock -> 3, NumberSeparator -> " "] &; I just do not know how to make the separator small.
Oct
31
comment Avoid unnecessary truncation
I think it will be good idea to close this question, since it has an answer already, and post a new question specific to "How to make $PrePrint use AccountingForm with small space for Block separator". This way it will be more specific question, or rename the question, edit as needed.
Oct
31
comment Avoid unnecessary truncation
I think you can using MakeBoxes, but I am not good at that. AccountingForm allready supports setting of DigitsBlocks. Try this: AccountingForm[0.34*60000000, DigitBlock -> 3, NumberSeparator -> ","] But I do not know how to tell it to use small space for separator. Using NumberSeparator -> " " will make the space too large.
Oct
31
comment Avoid unnecessary truncation
You can use 0.34*60000000 // AccountingForm I do not know now to set this to be automatically applied to each number printed. see mathematica.stackexchange.com/questions/20373/… (I think the answer you want is there, just saw it)
Oct
31
comment Why does Mathematica not seem to know that $i^x$ cannot be equal to $0$?
On V 9.01, I get Simplify[2^x a == 0] as 2^x a ==0 not a==0 ? screen shot !Mathematica graphics
Oct
22
comment Differential equations: Solving a singular/nonlinear ODE using NDSolve
According to Maple, the system appears to be singular at the left point. It actually solved it analytical, with the trivial solution $y=0$. screen shot !Mathematica graphics (so basically your system is not well formed to solve) it suggested a mid-point numerical method. But I do not know now how to apply this in Mathematica NDSolve and it is there...
Oct
21
comment Setting up and solving system of equations
@SvendTveskæg use First command. updated.
Oct
21
comment Setting up and solving system of equations
@SvendTveskæg Expand is not needed. I was doing something else before and left it there. Yes, you can remove the Expand command. It does not do anything. Will update. Thanks.
Oct
20
comment How do I evaluate a symbolic integral involving Hermite polynomials?
Even after the correction in exp to Exp, it is not possible to get analytical solution. !Mathematica graphics after about 3 minutes trying... also Maple 17 not able to do it. To help find such syntax errors, I always look at the equation for the green colored symbols (or is this blue colored? I always mix green with blue). If the symbol is not black colored, then it means Mathematica does not know about it. You could have seen that exp was green colored, this means Mathematica does know about it.