8.12 October 15, 2013
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Top new questions this week:
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[Strip waste braces in nested
list]\url{http://mathematica.stackexchange.com/questions/33837/strip-waste-
braces-in-nested-list}
I have nested lists wherein there are a lot of waste levels which looks
like
l = {{{{{{2, 2}}, 3}, 2, {{2, 33}}, 4, 5}}};
I would like to reduce it to somthing like
l = {{{2, 2}, 3}, 2, {2, 33}, ...
- asked by (16 votes), answered by Leonid Shifrin (19
votes)
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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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[Mathematica gives wrong result while Wolfram|Alpha is
correct]\url{http://mathematica.stackexchange.com/questions/33866/mathemati
ca-gives-wrong-result-while-wolframalpha-is-correct}
Why does Mathematica and Wolfram|Alpha give different results based upon
the same code?
I know Wolfram|Alpha's 7.85 is correct.
- asked by dansu (11 votes), answered by Michael E2 (12 votes)
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[Replace elements in list not matching elements of another list at the
same
position]\url{http://mathematica.stackexchange.com/questions/33731/replace-
elements-in-list-not-matching-elements-of-another-list-at-the-same-posit
> }
I would like to compare two arrays:
m = {a,b,c,d,d,f};
n = {b,b,a,d,d,e};
and get:
{0,b,0,d,d,0}
I have tried all kinds of things, like:
m = {a,b,c,d,d,f};
n = {b,b,a,d,d,e};
Transpose[{m, ...
- asked by martin (11 votes), answered by Leonid Shifrin (18 votes)
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[How can I type-check the arguments of a Mathematica
function?]\url{http://mathematica.stackexchange.com/questions/33884/how-can
-i-type-check-the-arguments-of-a-mathematica-function}
(For educational purposes) I defined the following functions:
Translation (in $\mathbb{R}^2$):
trM[vec_] := {{1, 0, vec[[1]]}, {0, 1, vec[[2]]}, {0, 0, 1}}
Rotation (in $\mathbb{R}^2$):
...
- asked by ndroock1 (10 votes), answered by RunnyKine (6 votes)
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[How to bend a logarithmic number line into a
circle]\url{http://mathematica.stackexchange.com/questions/33924/how-to-ben
d-a-logarithmic-number-line-into-a-circle}
One way to plot a sequence of numbers on a logarithmic number line is
this:
LogLogPlot[0, {t, 8, 16}, Axes -> {True, False},
Ticks -> {{8, 9, 10, 11, 12, 13, 14, 15, 16}}]
How can the ...
- asked by Bogdan (9 votes), answered by ybeltukov (4 votes)
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[Is there a way to find out who is importing a
package?]\url{http://mathematica.stackexchange.com/questions/33949/is-there
-a-way-to-find-out-who-is-importing-a-package}
After calling some functions, if I look into $ContextPath, I can see
that JLink` is in there. Is there a way to find out what sequence of
functions calls (like a stack-trace) imported a particular ...
- asked by Adal (9 votes), answered by Leonid Shifrin (8 votes)
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Greatest hits from previous weeks:
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[How can I extract data points from a black and white
image?]\url{http://mathematica.stackexchange.com/questions/3831/how-can-i-e
xtract-data-points-from-a-black-and-white-image}
Consider the following graph (source):
Is there any way to extract the data points from this image in a
semi-automatic way? I have seen, and tried the methods suggested in this
question, but they ...
- asked by Eli Lansey (29 votes), answered by Sjoerd C. de Vries (33
votes)
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[Finding the centroid of the area between two
curves]\url{http://mathematica.stackexchange.com/questions/17170/finding-th
e-centroid-of-the-area-between-two-curves}
When I have an area bounded by curves, is there a built-in way to find
the center of the area? Or do I have to plot it first and then use
ComponentMeasurements on it?
For example: the area under $y= ...
- asked by a3f (10 votes), answered by george2079 (3 votes)
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Can you answer these?
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[How can I find the source of a memory
leak?]\url{http://mathematica.stackexchange.com/questions/33707/how-can-i-f
ind-the-source-of-a-memory-leak}
I found a really weird issue using NDSolve`ProcessEquations inside
module.
We start by setting HistoryLength to 0. After this we define a function
which takes in an integer and creates a Table of ...
- asked by jaclea (4 votes)
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[Is there something like
MaxProcessorUsed?]\url{http://mathematica.stackexchange.com/questions/33775
/is-there-something-like-maxprocessorused}
For standard procedures it is easy to test if the implementation is
better or worse than other by using Timing etc.
It does not help us with creating Dynamic interfaces/visualisations.
Sometimes it ...
- asked by Kuba (5 votes)
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[How does Mathematica estimate error on fit
parameters?]\url{http://mathematica.stackexchange.com/questions/33685/how-d
oes-mathematica-estimate-error-on-fit-parameters}
When performing a fit using NonlinearModelFit (or any of Mathematica
fitting functions, but I am particularly interested in nonlinear
models), Mathematica makes a covariance matrix available for all ...
- asked by ydl (1 vote)