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Sep
12
comment Simplifying a trigonometric sum
@m_goldberg I was doing my HW's in the other side :(, must have sneeked in without my noticing. Will fix now
Sep
12
comment Method -> {“AxesInFront” -> False} for Graphics3D
fyi, I do not get the same image in your first draw. I get this !Mathematica graphics (on winows 7, V 9.01)
Sep
11
comment Sum[expr,{i,0,Infinity}] for power series of cumulative normal distribution gives exponential function?
on V 9.01 on windows, the sum does not evaluate. I copied what you had there. screen shot: !Mathematica graphics it always helps to say what version and platform you are using.
Sep
10
comment Convolution of two distribution functions
@SjoerdC.deVries I just copied what OP wrote and did not even notice the exp vs. Exp ;) , oh boy, now I look at it, I see more syntax errors , using "(" vs. "[" . I need to go make some strong coffee
Sep
10
comment Convolution of two distribution functions
Convolve[f, g, x, y] gives zero (y is the convolution dummy variable)
Sep
10
comment Turn expression into function
....on the side effect, it is done by documentation. Each function should document any side effects it makes. Things like creating a file, or updating a file, and such are considered a side-effect and can't be prevented by the language. But should be documented in the function header, so someone reading this function later on, can see right away what are its side-effects.
Sep
10
comment Turn expression into function
@jVincent no, I meant true function, not pure. true function in the mathematical sense. it only acts on its input via arguments, and has local variables and has no side effects other than its return value. A true function does not even allow passing argument by reference. Ada functions used to be true, until Ada 2012 where they relaxed allowing a function to be passed an argument by reference (called in-out). Many in Matematica write functions that are not true functions, where some of its input is passed by arguments and some of its input is global.
Sep
9
comment Why the EuclideanDistance of these 2 exact points generates the warning N::meprec?
Yes, same thing on my computer also, kernel actually crashed and I got an error message from C++ library. I did not say this will work, I said to try it :)
Sep
9
comment Why the EuclideanDistance of these 2 exact points generates the warning N::meprec?
see See wolfram.com/learningcenter/tutorialcollection/… page 20 for more discussion.
Sep
9
comment Why the EuclideanDistance of these 2 exact points generates the warning N::meprec?
No, not a bug. This is how Mathematica works. I think it is similar issue as this one mathematica.stackexchange.com/questions/31822/…. If you do this: $MinPrecision = $MachinePrecision; $MaxPrecision = $MachinePrecision; EuclideanDistance @@ pts the warning goes away. Mathematica needed more than 50 precision to decide on this one. That is all. You can also try $MaxExtraPrecision = Infinity; EuclideanDistance @@ pts but then you have to wait long time....
Sep
8
comment Specify values for X-axis and Y-axis ticks and control their format
Which version are you using?
Sep
8
comment How to pick a solution from a list of solutions using a test?
solutions=x /.Solve[f[x] == 0, x]; Pick[solutions/. b3 -> 2,Min[solutions]/.b3 -> 2] gives {1}. You need to do the replacement before Pick uses them.
Sep
8
comment How to extract data from contour plot as a text file?
@SjoerdC.deVries if the coordinates is what is needed, I updated the answer. thank you.
Sep
8
comment How to extract data from contour plot as a text file?
@MMM I do not follow you. Where did this 2 columns come from and what they represent? May be all what you needed then is a simple Table command. You have to be clear what is it you want as I am not really following you.
Sep
8
comment How to extract data from contour plot as a text file?
You asked for contour data. The above is the contour data. There are 11 rows. One for each contour.
Sep
8
comment How to keep markers as dots in a joined ListPlot?
fyi, can also use the new command ListLinePlot for this. No difference for this case. ListLinePlot[data, ImageSize -> 700, PlotMarkers -> {Automatic, 12}] !Mathematica graphics
Sep
7
comment Manipulate graphs in 3D
If one right-clicks on the image, then a pop-up menu comes up. One option is convert to graphics. I am just not able to find what Mathematica command actually is used to do this so that one can program it in. Strange. Any one knows the actual command used by that menu to convert it to Graphics object? (I never used CompleteGraph before)
Sep
7
comment How to make Mathematica try harder to perform symbolic comparisons?
I do not know if following will work for you or not, but myself, I like to keep everything in MachinePrecision only to be able to compare things with Matlab and Fortran when I want to. You can force all computation to be in MachinePrecision by putting this at the top of the notebook or in your init.m $MinPrecision = $MachinePrecision; $MaxPrecision = $MachinePrecision; Now your example runs with no warnings: !Mathematica graphics again, do not know if this is what you want, or this will work for what you are doing.
Sep
6
comment Manipulate executes expressions multiple times
@leibs the default is Full for tracking for Manipulate. And from help on TrackedSymbols it says on this option: symbols that appear explicitly in the input expression (notice the word appear explicitly). In the example above, x and y are these. They are global variables, but appeared in the expression also, hence they were tracked automatically.
Sep
6
comment Faster Eigenvalues with lower precision goal
@RahulNarain good point. I did not notice this difference for MachinePrecision syntax, I'll update the result for MachinePrecision now...This shows that Default is fastest (which is almost the same as using MachinePrecision, but need more runs to verify, which I am doing now....)