21,746 reputation
13073
bio website
location
age
visits member for 2 years, 9 months
seen 6 mins ago

Oct
8
revised Using mathematica to understand linear algebra
make the point sphere
Oct
8
revised Using mathematica to understand linear algebra
clean
Oct
8
answered Using mathematica to understand linear algebra
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?
Oct
5
comment Attempt to solve for Differential Equation - Acc, Vel, Pos in (x,y,z)
it will be easier for someone to help you if you give the full code, which includes calling the function you have above. btw, in Mathematica functions are normally defined using := not =.
Oct
1
comment Outputting numbers symbolically
Table[HoldForm@2^n, {n, 1, 5}] !Mathematica graphics
Oct
1
comment Disable alert message with internet connectivity off
I have the same problem also. But it is a harmless beep that shows up only at start time, so it was easier to just ignore it than try to find how to turn it off :)
Oct
1
comment Using variable values from Manipulate in later Plots etc
Easy way around, is to use different symbol, since "t" is used as a free parameter inside Manipulate. From outside, refer to it as say "z", like this: Manipulate[ z = t /. First@NSolve[ Rationalize[Integrate[PDF[StudentTDistribution[0, 1, df], x], {x, -t, t}] == vertrauensintervall/100], t, Reals], {df, 3, 30, 1, Appearance -> "Labeled"}, {vertrauensintervall, 68.270, 99.73, 1, Appearance -> "Labeled"}, ContinuousAction -> False, LocalizeVariables -> False ] screen shot: !Mathematica graphics ps. need to @name to ping one so they hear you
Oct
1
comment ComplexExpand does not treat everything as real number
@belisarius I found a reference. Here it is reference.wolfram.com/language/guide/VariablesAndFunctions.html The symbolic language paradigm of the Wolfram Language takes the concept of variables and functions to a new level. I am sure there might be more exact definition somewhere, May be in the Wolfram Mathematica original book itself? I do not know.
Oct
1
comment ComplexExpand does not treat everything as real number
the help says expands expr assuming that all variables are real notice the word variables. I do not think D[f[X],x counts as a variable. Do you? (since it does not know what f[x] is defined as.
Oct
1
comment Using variable values from Manipulate in later Plots etc
That is because you did not make 't' variable. Try adding t /. First@NSolve[....] to your code
Oct
1
comment Using variable values from Manipulate in later Plots etc
...but to answer your question: If you add LocalizeVariables -> False then all Manipulate control variables can be used outside Manipulate. i.e. they are no longer localized. Not a good way to do things if you ask me, but if that is what you want, this is an option.
Oct
1
comment Why PlotStyle->Dashed make everything dashed?
No problem on windows using 10.01, screen shot !Mathematica graphics
Oct
1
comment Using variable values from Manipulate in later Plots etc
Why are you even using Manipulate for this? A simple Table command can be used to generate the data. data = Table[ {t /. First@NSolve[ Rationalize[Integrate[PDF[StudentTDistribution[0, 1, df], x], {x, -t, t}] == vertrauensintervall/100], t, Reals], df}, {df, 3, 5, 1}, {vertrauensintervall, 68, 74, 1} ] It does not make sense to use Manipulate sliders to generate the data, since you can move the sliders in non-uniform ways, unless you want to plot one point at a time.
Oct
1
answered Add text after label in a Manipulate graphic
Sep
30
awarded  Explainer
Sep
28
answered Using Plot inside If statement