11,296 reputation
22856
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location Munich, Germany
age 36
visits member for 3 years
seen 7 hours ago

I work at a small mechanical engineering company, where I develop software and image processing algorithms for camera-based inspection machines.


Jul
12
revised Dynamic with RegionNearest keeps one CPU core at 100% - Is this a bug?
added 305 characters in body
Jul
12
comment Dynamic with RegionNearest keeps one CPU core at 100% - Is this a bug?
@Nasser: My original code had a LocatorPane to move pt around, containing a Graphics that showed a line from pt to the nearest point, and a RegionPlot of the intersection. I've simplified it to find the root problem, and only posted that. You can imagine a Locator moving pt around somewhere else in the notebook, but it doesn't really change anything.
Jul
12
asked Dynamic with RegionNearest keeps one CPU core at 100% - Is this a bug?
Jul
11
comment Can StringTemplate be extended to offer printf-like formatting capabilities?
@m_goldberg: Maybe that sentence was a bit snarky ;-) Anyway, I can see the reasoning of offering no string template functionality, at least for a compiled language. (I'm not sure how you would write a large-scale application that can be localized to a dozen languages, but that's not the point here.) But MMA has string templates. It's just missing formatting options. As far as I can see, that doesn't make it safer, only harder to use.
Jul
11
asked Can StringTemplate be extended to offer printf-like formatting capabilities?
Jul
11
answered Can StringTemplate be extended to offer printf-like formatting capabilities?
Jul
7
comment Can I use symbolic tensors for simple linear algebra and calculus?
@Szabolcs: I've noticed that Dt[f.g, x] is f.Dt[g, x] + Dt[f, x].g: MMA seems to apply the product rule to Dot, so I'd say the 1 in 1 . x should be the Jacobian D[x,x], i.e. IdentityMatrix. (Did that make sense?). So I could probably safely replace Dot[x_,1] -> x. But I can't get the transpositions right, because D doesn't seem to work with Transpose, Transpose doesn't distribute over sums and so on.
Jul
7
revised Can I use symbolic tensors for simple linear algebra and calculus?
Tensor notation add
Jul
7
asked Can I use symbolic tensors for simple linear algebra and calculus?
Jul
4
awarded  Nice Answer
Jul
4
comment Why are functions called first-class objects in Mathematica?
@Eric: You can use Attributes[Set] to find out which arguments are evaluated: It has the HoldFirst attribute, so the first argument isn't evaluated. You could write Evaluate[{g, h, j}[[1]]] = 6, though.
Jul
4
revised Why are functions called first-class objects in Mathematica?
added 35 characters in body
Jul
4
comment Why are functions called first-class objects in Mathematica?
@Eric: I've added a new paragraph about how "variables" and "functions" are basically treated the same way.
Jul
4
revised Why are functions called first-class objects in Mathematica?
added 1754 characters in body
Jul
4
comment Why are functions called first-class objects in Mathematica?
@Eric: I didn't doubt that you can parse the expression tree. A C programmer can parse expression trees, too. The point is: The C programmer will rarely handle expression trees at runtime, unless she's writing a compiler. In Mathematica, you handle expression trees all the time.
Jul
4
comment Why are functions called first-class objects in Mathematica?
@acl: The documentation is great once you get the computational model. But I must admit that I had a lot of trouble understanding it at first, when I started with all the (mis)conceptions about what expressions, functions and values are, coming from C++.
Jul
4
answered Why are functions called first-class objects in Mathematica?
Jul
4
comment Why are functions called first-class objects in Mathematica?
Try to parse the expression x=(Sin + Cos)[a] - are Sin/Cos values or functions here? They're added like values, after all. Is Plus a function? Since it is "called" with [a]. Now call Through[x], and you'll get a perfectly sensible mathematical expression. Being able to manipulate expression trees like that is extremely useful.
Jul
2
awarded  Curious
Jun
18
awarded  Nice Question