7.45 February 4, 2014
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Top new questions this week:
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[Extracting angles from a simple
picture]\url{http://mathematica.stackexchange.com/questions/41563/extractin
g-angles-from-a-simple-picture}
I'm not sure if this is even possible with Mathematica, but I want to
extract the angles between all lines in this picture:
It consists of $12$ lines, so I want a matrix with $144$ entries. I ...
- asked by holistic (13 votes), answered by Kuba (14 votes)
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[Shuffle product of two
lists]\url{http://mathematica.stackexchange.com/questions/41614/shuffle-pro
duct-of-two-lists}
I want to do the following: I have two lists {a_1,...a_n}, {b_1,...,b_n}
and I would like to build now all shuffles out of this. This means all
unions of these lists while still keeping the individual ...
- asked by A friendly helper (12 votes), answered by Mr.Wizard (9 votes)
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[Strange behavior when using Row with packed
arrays]\url{http://mathematica.stackexchange.com/questions/41653/strange-be
havior-when-using-row-with-packed-arrays}
Today I lost a lot of time with a strange behavior and I narrowed it
down to this small piece of code:
a = {1, 2};
ToString@Row[DeleteDuplicates[a], ","]
ToString@Row[Union[a], ","]
"Row[{1, 2}, ...
- asked by Murta (11 votes), answered by Szabolcs (11 votes)
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[Graphics`Mesh`FindIntersections[ ] fails to detect
intersections]\url{http://mathematica.stackexchange.com/questions/41496/gra
phicsmeshfindintersections-fails-to-detect-intersections}
Graphics`Mesh`FindIntersections[ ] is an undocumented function for,
well, detecting intersections very efficiently. Take a look:
i = Import@"http://i.stack.imgur.com/PcWcz.png";
perim = ...
- asked by belisarius (10 votes)
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[Checking through an
expression]\url{http://mathematica.stackexchange.com/questions/41324/checki
ng-through-an-expression}
I am writing a code that manipulates expressions that contains functions
with an arbitrary number of arguments. An example expression is
expr = x f[a, b, c, d] - 4 f[b, a, d] + z f[] + f[a, b, d] - ...
- asked by QuantumDot (7 votes), answered by Artes (5 votes)
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[LengthWhile until first
duplication]\url{http://mathematica.stackexchange.com/questions/41469/lengt
hwhile-until-first-duplication}
I have the need to trim each of a large number of potentially very long
lists (10^6+ elements) to the length where the last occurrence of any
distinct element happens, or said another way, where the ...
- asked by rasher (7 votes), answered by rasher (2 votes)
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[Why do I get a different value when I change the order of
integration?]\url{http://mathematica.stackexchange.com/questions/41454/why-
do-i-get-a-different-value-when-i-change-the-order-of-integration}
I think the following two-dimensional integrals should be equal, since
they both integrate the function over the half plane defined by
$t>\tau$.
$$\int_{-\infty}^\infty \mathrm{d}t ...
- asked by Jason B (7 votes), answered by Michael E2 (9 votes)
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Greatest hits from previous weeks:
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[How to get intersection values from a parametric
graph?]\url{http://mathematica.stackexchange.com/questions/33947/how-to-get
-intersection-values-from-a-parametric-graph}
I have this graphed:
ParametricPlot[{2.4*Cos[t] + 1.6*Cos[3 t/2], 2.4*Sin[t] - 1.6 Sin[3
t/2]}, {t, 0, 4*Pi}]
It is a star, and the lines cross each other twice in the third
quadrant. I need to ...
- asked by guest (14 votes), answered by Artes (17 votes)
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[Finding the best way to visualize rather complicated
data]\url{http://mathematica.stackexchange.com/questions/33429/finding-the-
best-way-to-visualize-rather-complicated-data}
I have the following data
data = {{7.5, 12.45, 12.45, 12.75, 12.75, 12.25, 12.25, 12.53, 12.53},
{8.5, 12.22, 12.22, 12.23, 12.23, 13, 13, 12.54, 12.54},
{9.5, 11.58, 11.53, 12.75, 13.48, 12.39, ...
- asked by Vaggelis_Z (12 votes), answered by Pinguin Dirk (10 votes)
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Can you answer these?
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[Load a Mathematica Notebook using .Net
code]\url{http://mathematica.stackexchange.com/questions/41410/load-a-mathe
matica-notebook-using-net-code}
I have gotten a tremendous amount of information from the question
posted at (Load a Mathematica Package via .Net code), which my
application is very similar to. Specifically in that thread, the ...
- asked by Josh (1 vote)
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[Trying to find the best Pade approximant for a given numer of
terms]\url{http://mathematica.stackexchange.com/questions/41620/trying-to-f
ind-the-best-pade-approximant-for-a-given-numer-of-terms}
Let suppose that I have a function $f[x]$ I want to approximate using a
Pade expansion and that I decide what would be maximum number of terms
to be used.
Is there any way with Mathematica to find ...
- asked by Claude Leibovici (1 vote)
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[Estimation of vector autoregressive (VAR)
process]\url{http://mathematica.stackexchange.com/questions/41330/estimatio
n-of-vector-autoregressive-var-process}
To estimate 1-dimensional VAR process (which is AR process) you can
easily use functions EstimatedProcess or FindProcessParameters like
this:
sample = RandomFunction[ARProcess[{.2,-.4},.1], {1,300}];
...
- asked by matt525252 (3 votes)