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Oct
2
comment Replacing columns of a matrix with zeros
I suppose you could do something like this then MapAt[#*0&,list1,{All,1;;3}]
Oct
1
comment Outputting numbers symbolically
Inactivate[Table[2^n, {n, 1, 5}], Power] (I am not obsessed with Inactive I promise)
Oct
1
comment Strange style conversion indicator appeared when type “a Pre”
From reference.wolfram.com/language/ref/CodeAssistOptions.html it looks like the option is "AutoConvertEnable".
Oct
1
comment How to regress negative log?
Something like NonlinearModelFit[data, -p2 Log[p1 x],{p1,p2},x] where p1 and p2 are parameters?
Oct
1
comment Spherical parametric plot
If you have version 9+ you can use: ParametricPlot3D[Evaluate[CoordinateTransform[ "Spherical" -> "Cartesian",{2 Cos[t]+Sin[t],t,Sin[10 t]}]],{t,0,Pi/2}]
Oct
1
comment How to simplify symbolic matrix multiplication using the associativity of scalar multiplication?
This may be too specific: Thread[(2 A).(3 B), Times] /. Dot[a_?NumericQ, b_?NumericQ] :> a b
Sep
12
comment Join decimal part
just beat me to it, yours is the same as mine (essentially):toDecimal[a_, b_] := N[a + (-1)^Sign[a] b 10^(-IntegerLength[b])]; list /. {a_, b_, c_, d_} :> {toDecimal[a, b], toDecimal[c, d]} (* {0.1, -2.259} *)
Aug
27
comment Numerical value of physical constants Mathematica 10
you can also use QuantityMagnitude to get the value out.
Aug
27
comment Numerical value of physical constants Mathematica 10
or In[647]:= UnitConvert[Quantity[1, "PlanckConstant"], "eV*s"] Out[647]= Quantity[4.135668*10^-15, "Electronvolts" "Seconds"]
Aug
27
comment Numerical value of physical constants Mathematica 10
what would you like the result to be, i.e. which units should it be with respect to?
Aug
22
comment Window ▶ Show Handwriting Input
Have you turned on the "Tablet PC Components" in Windows 7?
Aug
5
comment Integral too slow and with conditionals
use assumptions Integrate[x/(x^2 + y^2)^(3/2), {y, -a, a}, Assumptions -> (x | y) \[Element] Reals && x > 0 && a > 0]. This is likely a duplicate, but I can't find which one.
Aug
5
comment No menu in Mathematica 10 under Ubuntu 14.04
What is the result of the following? AbsoluteOptions[EvaluationNotebook[], WindowElements]
Jul
30
comment Why does Fourier give a shifted frequency?
@xslittlegrass, actually it was the second part in the answer: "in addition, the discrete fast Fourier transform assumes periodicity."
Jul
30
comment Why does Fourier give a shifted frequency?
possible duplicate of Plotting the frequency spectrum of a data series using Fourier
Jul
29
comment How to know at which point of a calculation I am while using Table
Table[n = i; Pause[1]; foo[i], {i, 0, 10}]; Labeled[ProgressIndicator[Dynamic[n], {0, 10}], Dynamic[n], Right] for overkill
Jun
30
comment Specifying non-conflicting PlotTheme options
I would certainly report your difficulties to support@wolfram.com
May
9
comment Simplify with Assumptions Sqrt[(expr)^2]
PowerExpand[Sqrt[(x - y + a b c)^2]] perhaps, with all of the caveats of PowerExpand.
May
8
comment How can I tell how much memory is taken by an expression?
What do you get from evaluating Developer`$MaxMachineInteger? I suspect this is a 32-bit thing.
May
7
comment Format and TeXForm does not work as expected
I would report this to support@wolfram.com