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visits member for 3 years
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geek, nerd, physicist.


Mar
25
comment How to find out where an error occurs?
@Alireza Before evaluating.
Mar
24
comment How to find out where an error occurs?
@Szabolcs Thanks for the tip!
Mar
24
comment How to find out where an error occurs?
Try the built-in debugger: Evaluation>Debugger with Break at messages checked.
Mar
23
comment Using lists for creating another list
By the way, if Sqrt in the example is a complex user-defined function foo, you may need to use SetAttributes[foo, Listable].
Mar
23
comment plotting a box in Mathematica
Manipulate[ Plot[h*UnitBox[x], {x, -0.6, 0.6}, PlotStyle -> {Red, Thickness[.004]}], {h, 0, 10}]
Mar
23
comment How could I add the WorldMap skin to this parametricPlot3d?
also the example here
Mar
23
comment How could I add the WorldMap skin to this parametricPlot3d?
refer to this post
Mar
23
comment Is there a bug in MatrixExp in Mathematica v10?
Confirmed the issue in ver.10. For your example specifically, since the matrix can be exactly diagonalized using Eigensystem, you can get a nice analytic expression--I'm assuming it's used in quantum mechanics where the matrix is the Hamiltonian (easily diagonalized in your example) and you want the unitary propagator with MatrixExp.
Mar
20
comment Selective update of mySQL database column
The code you posted has mismatching quotes after # to begin with.
Mar
20
comment ReadList and ToExpression
The underscore _ as a pattern matching mechanism is reserved for mathematica.
Mar
18
comment Numerical integration and plotting
The OP wants to plot fC as a function fP, maybe like ParametricPlot[{fC[a],fP[a]},{a,0,5}]?
Mar
12
comment Combining 2D slices into a 3D plot
@Nick If you only care about the final output, you could, in theory, put the data of your 2D slices in a list and replace g=Table[...] with g=ListPlot3D[...] in my answer. It's not exactly stacking 2D plots but the end result may look the same. For example, one way to get the data from Plot[...] is here.
Mar
11
comment Combining 2D slices into a 3D plot
@Nick I've made some changes according to your phase diagram context.
Mar
11
comment Combining 2D slices into a 3D plot
@Nick I made some changes according to your phase diagram context. Is this what you want?
Mar
10
comment Simplify complex answer given by DSolve[]
Using the code in your first block does not give a very good result because strictly speaking E^Integrate[g[K[1]], {K[1], t, K[2]}] includes the integrate index K[2] and should be included in the last Integrate[h[K[2]], {K[2], 0, t}]. Following your idea, the second replace rule in xf function should be coeff_*Integrate[int_,{x_, a_, b_}] :> Integrate[coeff*int,{x, a, b}]
Feb
20
comment ListPlot3D not working for very small numbers
@drabus Also use PlotRange->All in this solution because some data points are not shown. Or refer to my answer which does not need rescaling.
Jan
9
comment Let mathematica combine integral limits
@george2079 Excellent! Problem solved.
Jan
8
comment Let mathematica combine integral limits
Thanks! It works for Integrate[f[t], {t, a, b}] + Integrate[f[t], {t, b, c}] but not -Integrate[f[t], {t, b, a}] + Integrate[f[t], {t, b, c}].
Jan
6
comment Forward function arguments to built-in Plot[]
@kguler foo2 works perfectly.
Jan
6
comment Forward function arguments to built-in Plot[]
@kguler thanks, but foo[Sin[t] + I*Cos[t], {t, 0, 10}, PlotRange -> All] does not work on my machine (output is exactly "foo[Sin[t] + I*Cos[t], {t, 0, 10}, PlotRange -> All]").