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Oct
18
comment Getting a blank plot when plotting two functions with Plot3D
Your code is not valid for copying. Try posting it again. Copy the as cell as plain text. For best result, convert the cell to InputForm before. (backup your cell before, just in case). ps. no need to make the title all UPPERCASE, it appears as if you are shouting when doing this.
Oct
12
comment StateResponse is non-deterministic
@Mathxy btw, It might be a good idea to send this to support@wolfram.com.
Oct
12
comment StateResponse is non-deterministic
@Mathxy As I said, I do not know internally what happens. CLearly this is a bug, but you asked for a workaround. There was some changes in v10 with processing of diracdelta's in control system. May be this is related. See mathematica.stackexchange.com/questions/57891/…
Oct
12
comment Why this gives 0?
@Anixx that is correct, that is why I used ExpToTrig to make it generate a result. Ofcourse Exp[t] and ExpToTrig[Exp[t]] are the same thing, mathematically speaking. But one gives a result and one does not. That is why. Just to see the zero come out. Else will not see it.
Oct
12
comment Why this gives 0?
I did not notice the /w. But still, I do not see how it the final result should be Sinh[x]. I think the 0 is not correct and I know why it does it, but I do not see how you came up with Sinh[x] either. But not important. I think 0 is not correct.
Oct
12
comment Why this gives 0?
Can you explain why the result should be sinh(x)? Lets assume all is perfect, and so InverseFourierTransform[FourierTransform[Cosh[t]]] should in theory return back Cosh[t], right? (inverse(fourier(foo))) is foo. Then why is I*Cosh[h]=Sinh[x]? Where did this come from?
Oct
12
comment How to export a text into eps without splitting
it works fine for me. Version 10.01 on windows.
Oct
11
comment How do I find the expression for where the first derivative equals 0?
Mathematica does not have Sqr function. !Mathematica graphics I am using V 10.01
Oct
10
comment Epilog with text not shown
You are telling it to put the text at {-12,10} but you are saying the plot range should be {-10,10} ? So it will not show up. Try Plot[x^2, {x, -13, 10}, Frame -> True, Epilog -> {Text[Style["S", FontFamily -> "Helvetica", Black, Bold, 20], {-12, 10}]}]
Oct
10
comment Convert matrix of strings to matrix of numbers
s = {"425060", "0.214235E+07", "0.48", "0.01", "0.39", "0.49", "0.01", "0.38", "1.64", "-1.65", "-2.13", "518"}; InternalStringToDouble[#] & /@ s`, see mathematica.stackexchange.com/questions/1737/…
Oct
10
comment Getting unwanted solution from Solve
Solution 3 is a result of solution 2 I do not understand what this means. Each one is an independent solution. You do not obtain one solution from another? Solution 4th is correct. Try: vars = {x[1], x[2], x[3], x[4], x[5], x[6], x[7]}; eqs = {x[7] == 0, 6 x[4] x[5] + 6 x[3] x[5] x[6] + z*x[4] x[7]^2 + z*x[4] x[5] x[7]^2 == 0}; sol = Solve[eqs, vars]; eqs /. sol[[4]] and this gives True. If you want solution over reals only, add the options Reals
Oct
9
comment Importing multiple files with a loop
what is the first file name? is it datafile.20.0000.out? so what is the last file full name? is it datafile.20.1010.out ? You can't have an index that is not discrete. So index 20.1 will not work.
Oct
9
comment Importing data from Matlab, using data in “NSolve” and send the results back to Matlab
try matlink matlink.org
Oct
8
comment Converting image data to array
use the ImageData[] command img=Import["ExampleData/lena.tif"]; data=ImageData[img];
Oct
8
comment Matrix Rational Canonical Form
@Ryker this was over a year ago. So I do not remember now. But feel free to try it, and you find a bug you can report it and will try to fix it. Make sure to include the input and the expected output to help me fix it. As far as I know the code is supposed to work ok.
Oct
8
comment Using mathematica to understand linear algebra
@ybeltukov thanks for the hint. I changed the point to sphere. yes, it looks better.
Oct
8
comment the default option of NDSolve
You can do Options[NDSolve] and see the default values. It says Automatic for some. Then go to each and looks at its help. For Accuracy it says AccuracyGoal->Automatic normally yields an accuracy goal equal to half the setting for WorkingPrecision and for PrecisionGoal it says ->Automatic normally yields a precision goal equal to half the setting for WorkingPrecision SO they depend on setting for WorkingPrecision Then you look at help for WorkingPrecision
Oct
8
comment Is there a command like meshgrid in Mathematica?
see mathematica.stackexchange.com/questions/30701/… "simulate-matlabs-meshgrid-function"
Oct
8
comment Matrix Rational Canonical Form
@Ryker I do not understand your question. The code is correct, unless you show otherwise. It produces the same result as on wiki, link above.
Oct
8
comment Using mathematica to understand linear algebra
First, you have error in the API, you wrote {{2 x - y, -x + 2y - z, 0 - 3 y + 4 z}, {x, -20, 20}} notice, you included a range specs inside the functions. i.e. you included {x, -20, 20} where it does not belong. Second, what is the parameters you are using? The helps shows that max of 2 parameters can be used, u and v. Are you sure ParametricPlot3D is what you want to use?