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Nov
15
revised Can we teach Mathematica about functional differentiation?
Added package loading instruction
Nov
15
revised Can we teach Mathematica about functional differentiation?
Forgot a replacement
Nov
15
comment Awkward output of TeXForm
That's the same thing that NumberFormat does. Here the main point is that you want the flexibility provided by NumberForm to introduce, e.g., the \cdot multiplication symbol.
Nov
15
revised Can we teach Mathematica about functional differentiation?
Added more instructions on how to use `VariationalD`.
Nov
14
answered Awkward output of TeXForm
Nov
13
answered Can we teach Mathematica about functional differentiation?
Nov
12
revised How can I differentiate Numerically?
Use ArrayPad instead of Part - looks cleaner.
Nov
12
comment How can I differentiate Numerically?
@DanielLichtblau If I look at this Wolfram demo, it seems to me that the technique is better classified as a symbolic differentiation trick. But maybe that's a matter of taste. My criterion would be that a numerical differentiation should be able to deal with functions that are calculated by numerical root finding, or using FixedPoint etc. Automatic differentiation requires that the function be calculable using elementary operations.
Nov
11
comment How can I differentiate Numerically?
@acl, yes - and I had upvoted your linked answer back then, too! It's very exhaustive.
Nov
11
comment NDSolve with vectors
Yes, I guess one could change the function argument from p0_ to {p0x_, p0y_, p0z_} etc., but it seems that even then the second-order differential equation is too hard to recognize as vectorial. So your approach is just the safest, I think.
Nov
11
answered How can I differentiate Numerically?
Nov
11
comment NDSolve with vectors
This is also how I would have done it, but it should probably be pointed out that Mathematica does know how to deal with vector functions in some cases. See e.g. this answer.
Nov
10
comment Simple ways to evaluate a derivative at a point?
You may find this question useful, too.
Nov
10
comment Simple ways to evaluate a derivative at a point?
This formatting is also found in my answer here, where I give another link to the Wolfram Blog.
Nov
10
revised How to change coordinates of a differential operator?
Removed an unnecessary step: Cartesian components were already in the list l.
Nov
10
answered How to change coordinates of a differential operator?
Nov
9
answered Uniform scaling of a Table of Graphics objects?
Nov
9
comment Selecting a Point that has the Lowest Absolute x/y-coordinate From a List of Points
Oh, right. I'm solving a different problem - If I do my approach for each component separately, I think your f6 wins the speed comparison again.
Nov
9
comment Selecting a Point that has the Lowest Absolute x/y-coordinate From a List of Points
Interesting comparisons. For your last one, f6, I got an additional speed boost by omitting the unused coordinates from the argument of Ordering: f7=Extract[#1,Ordering[Abs[#1[[All,1]]],1]]&.
Nov
5
comment Passing a function as an argument of another function
I just realized I had answered almost the same thing before: Pass function or formula as function parameter