8.21 April 22, 2013
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Top new questions this week:
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[Undocumented form for
Extract]\url{http://mathematica.stackexchange.com/questions/46261/undocumen
ted-form-for-extract}
Prompted by a comments conversation here, here's an interesting (and
often performance enhancing) use of Extract:
target = Join[Range[100], {{1, 2, 3, Range[20]}}];
Rest@Extract[target, {{{}}, {2 ;; ...
- asked by rasher (17 votes), answered by Jacob Akkerboom (7 votes)
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[Bizarre behavior of With, Compile and
Break]\url{http://mathematica.stackexchange.com/questions/46315/bizarre-beh
avior-of-with-compile-and-break}
I'm guessing this is almost certainly a bug in Compile (because they're
fairly common), but it's pretty weird and I spent about an hour tracking
down the issue and finding a test case. Consider this ...
- asked by Pillsy (10 votes), answered by Leonid Shifrin (10 votes)
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[Finding "Maxima" and "Minima" on a
B-Spline]\url{http://mathematica.stackexchange.com/questions/46517/finding-
maxima-and-minima-on-a-b-spline}
I need to find the "Maxima" and "Minima" on a B-Spline or more correct
the points where the 2nd components of the derivate equal zero.
For example:
g = BSplineFunction[{{1, 2}, {2, 4}, {3, -1}, ...
- asked by cxkoda (8 votes), answered by Silvia (12 votes)
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[Select cases from a
list]\url{http://mathematica.stackexchange.com/questions/46472/select-cases
-from-a-list}
I have a list in the form :
{1,1,1,0,-1,-1,1,1,1,0,0,0,0,-1,-1}
No I'm trying to select only those sequences which start with 1 have a
zero (or many zeros) between and are followed by -1. For ...
- asked by holistic (8 votes), answered by halirutan (11 votes)
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[Filling a curve between a line and the
x-axis]\url{http://mathematica.stackexchange.com/questions/46332/filling-a-
curve-between-a-line-and-the-x-axis}
I'm trying to plot the function $f(x)=\dfrac{1}{x^2}$, filling the
square area from (0,0) to (1,1) with purple and filling the area under
the curve from 1 to 4 with red.
However, Mathematica is not ...
- asked by Eudokia (8 votes), answered by Kuba (7 votes)
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[Explain the difference between ViewPoint and
ViewVector?]\url{http://mathematica.stackexchange.com/questions/46266/expla
in-the-difference-between-viewpoint-and-viewvector}
I've read the documentation, but am still very unclear as to what the
difference is between ViewVector and ViewPoint for Graphics3D. Could
someone explain it concisely and clearly enough so that an ...
- asked by Aron (7 votes), answered by Pickett (3 votes)
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[Measuring curve length on a binarized
image]\url{http://mathematica.stackexchange.com/questions/46342/measuring-c
urve-length-on-a-binarized-image}
With the help of almighty Mathematica 9, I got from this
To this:
with this code:
MorphologicalBinarize[
Import["http://i.stack.imgur.com/79l19.jpg"]~
ColorConvert~"Grayscale"];
...
- asked by iccthedral (7 votes), answered by halirutan (6 votes)
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Greatest hits from previous weeks:
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[How to generate a random
snowflake]\url{http://mathematica.stackexchange.com/questions/39361/how-to-
generate-a-random-snowflake}
'Tis the season...
And it's about time I posed my first question on Mathematica Stack
Exchange.
So, here's an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
- asked by Peltio (86 votes), answered by Silvia (117 votes)
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[What is the best Mathematica tutorial for young
people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the
-best-mathematica-tutorial-for-young-people}
As Conrad Wolfram said at the TED conference, in the future kids should
focus more on new technology. Computers compute better than humans, so
we should focus more on thinking and getting the ...
- asked by noisy (32 votes), answered by Vitaliy Kaurov (17 votes)
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Can you answer these?
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[How to get mathematica to simplify a
result]\url{http://mathematica.stackexchange.com/questions/46254/how-to-get
-mathematica-to-simplify-a-result}
I have the following output $\text{Li}_2\left(3-2 \sqrt{2}\right)-4
\text{Li}_2\left(-1+\sqrt{2}\right)$.
This turns out to be equivalent to
$\displaystyle\log^2(1+\sqrt{2})-\frac{\pi^2}{4}$.
How ...
- asked by Oliver (3 votes)
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[Why does Network`GraphPlot`wrapper appear in my
GraphPlot?]\url{http://mathematica.stackexchange.com/questions/46377/why-do
es-networkgraphplotwrapper-appear-in-my-graphplot}
I'm making a GraphPlot of data similar to this:
gpd = ...
- asked by ArgentoSapiens (1 vote)
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[Simplifying trig expressions containing Sqrt or
Abs]\url{http://mathematica.stackexchange.com/questions/46560/simplifying-t
rig-expressions-containing-sqrt-or-abs}
The following Maple code can simplify abs(sin(x)) into -sin(x) given the
condition -3Pi/4 < x < -Pi/2
simplify(abs(sin(x))) assuming -3*Pi < x, x < -5*Pi/2;
I tried what I thought would ...
- asked by mathe (6 votes)