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Apr
8
awarded  Nice Answer
Feb
28
comment How to define a function
something like f[u_[x_]] := x, but defining a function that takes as a second argument the derivative of the first is more involved.
Jan
31
awarded  Nice Answer
Jan
31
comment Does Mathematica support Laguerre Polynomials of Matrix Argument?
So operationally, you can think of MatrixFunction as taking a scalar function as the first arg, finding its series expansion, then using that to turn it into a matrix function and finally applying that to the second arg. If the second arg can eg be diagonalised via an orthogonal transformation, all you'd need to do do the transformation, apply a polynomial to the eigenvals and undo the transformation.
Jan
31
comment Does Mathematica support Laguerre Polynomials of Matrix Argument?
Oops you're right, LaguerreL is Listable so it just threads. OK, this does what you want I think: m = # + Transpose@# &@RandomReal[{-1, 1}, {10, 10}]; MatrixFunction[LaguerreL[3.2, #] &, m] (the idea is that MatrixFunction takes a scalar fn as the first arg, turns it into a matrix function and applies it to the second argument). Unless you actually do want a scalar as the output but then you need to explain how you want to get it.
Jan
30
comment Does Mathematica support Laguerre Polynomials of Matrix Argument?
it produces a 10 by 10 matrix of elements drawn from a uniform random distribution and then adds it to its transpose. I just wanted a symmetric matrix.
Jan
30
comment Does Mathematica support Laguerre Polynomials of Matrix Argument?
Apparently yes, eg m = # + Transpose@# &@RandomReal[{-1, 1}, {10, 10}]; LaguerreL[3.2, m] seems to work. In general you could also use MatrixFunction for this sort of thing.
Jan
20
comment Why is (-1.)^2. a complex number
@xslittlegrass I see. No idea then.
Jan
20
comment Why is (-1.)^2. a complex number
Look: Plot[{Re@#, Im@#} &@((-1)^x), {x, 1.5, 2.5}]
Jan
17
awarded  Yearling
Jan
7
awarded  Nice Answer
Dec
16
comment Can't type in notebook in version 10
The same thing happened to me a couple of times (also on OS X). Quitting Mathematica and restarting it fixed it both times. Interestingly, when I quit, it put up a dialog to save a few of the notebooks, and there I could interact with it (to click on yes or no). Very strange.
Nov
23
awarded  Good Answer
Oct
27
awarded  Good Question
Oct
14
revised Graph showing valid English words obtained by insertion of single characters
formatting
Sep
30
awarded  Explainer
Sep
19
awarded  Generalist
Sep
15
awarded  Nice Question
Aug
29
comment Integral of x^p
Oh right that's why it doesn't work in mathematica. Oops, pattern recognised the wrong thing, I'm an idiot sorry.
Aug
29
comment Integral of x^p
Actually the log is recovered in the limit. It's just that mathematica doesn't recover it correctly.