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May
18
answered How to create a column for ordering values
May
18
comment Animation of double pendulum
@jens I somehow managed to not note that :-(. Retracted my close vote. Nice answer BTW.
May
18
comment How to create a column for ordering values
@kguler I guess that should be Ordering[-values], given that the OP wants a descending sort
May
18
comment Animation of double pendulum
For a great introduction to Mathematica, have a look at Leonid Shifrin's free book. An extensive overview of additional Mathematica material can be found here.
May
18
comment Animation of double pendulum
Try this instead: sol = NDSolve[{2*phi1''[t] + phi2''[t]*Cos[phi1[t] - phi2[t]] + phi2'[t]^(2)*Sin[phi1[t] - phi2[t]] + 2*9.81*Sin[phi1[t]] == 0, phi2''[t] + phi1''[t]*Cos[phi1[t] - phi2[t]] - phi1'[t]^(2)*Sin[phi1[t] - phi2[t]] + 9.81*Sin[phi2[t]] == 0, phi1[0] == Pi/2, phi2[0] == Pi, phi1'[0] == 0, phi2'[0] == 0}, {phi1[t], phi2[t]}, {t, 0, 10}]. Since this seems to be a case of a simple error I'm going to vote to close this question (no worries, nothing negative).
May
18
comment Animation of double pendulum
I see one equation that has two == in it. Probably two equations that you have inadvertently merged. Ans it may be that in {phi1[t], phi2[t], t} you may have to drop the t part.
May
18
reviewed Reopen Combined Elliptic-Parabolic PDE in 1D
May
18
comment Plot a solid generated by a family of surfaces
@EverettKnag "the cross sectional area of the Z,y PLane at every height Z." You mean the cross sectional area of the Z,y plane for a given x value? If not, your question is a bit mysterious. As you phrase it, you are describing a line.
May
18
comment Plot a solid generated by a family of surfaces
If all is well, manually rotating a 3D plot in the FrontEnd is done by the graphics card. Calculating the plot itself, in parallel, using the GPU's processing units is not. There is no straightforward way to do this, other than writing the low-level programs to do that yourself. If you have done that CUDAlink provides tools to link that to Mathematica.
May
17
reviewed No Action Needed Need to parallelize function f in a iteration
May
17
comment How to count the number of n-gons and line intersections in an image of a complete graph?
Please note that for a given graph the number of intersections may vary with the choice of layout method. It's not an intrinsic property of a graph. Try for instance Graph[{1 -> 2, 1 -> 3, 1 -> 5, 2 -> 4, 2 -> 6, 3 -> 4, 3 -> 7, 4 -> 8, 5 -> 6, 5 -> 7, 6 -> 8, 7 -> 8}] and Graph[{1 -> 2, 1 -> 3, 1 -> 5, 2 -> 4, 2 -> 6, 3 -> 4, 3 -> 7, 4 -> 8, 5 -> 6, 5 -> 7, 6 -> 8, 7 -> 8}, GraphLayout -> "PlanarEmbedding"]. BTW Your graph can be generated simply by CompleteGraph[10].
May
17
answered Plot a solid generated by a family of surfaces
May
17
comment Plot a solid generated by a family of surfaces
CUDAlink doesn't let Mathematica magically run all its programs on the graphics card. Apparently you haven't read the documentation. It's used to accelerate a restricted set of functions and for running programs written in C specifically for the graphics card.
May
17
comment Mathematica script - Using front end
You're indeed using a lot of functions that require the FrontEnd. Not sure why you think you could run that without FrontEnd. If you want this kind of interactivity why don't you simply use a notebook?
May
17
reviewed Leave Open Transforming a huge rectangular table to Sparse Array
May
16
reviewed Approve Symbolic tensor product calculation
May
16
reviewed No Action Needed Transforming a huge rectangular table to Sparse Array
May
16
reviewed No Action Needed Plot3D Not Showing plot
May
16
comment Exp is slower for some number ranges
I see something similar though much more stratified (link). Win7-64 M9.0.1.
May
16
reviewed Close Getting data through a serial port