5.11 Tuesday, October 18, 2016

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Top new questions this week: 
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[Why removing a function and defining it on the same line does not work?] http://mathematica.stackexchange.com/questions/128818/why-removing-a-function-and-defining-it-on-the-same-line-does-not-work

Why do the two pieces of code below yield rather different results? The only difference is that in the first one the function definition is in the same line as the Remove command while in the second ...

- asked by Fernando Saldanha (17 votes), answered by dan7geo (16 votes)

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[House of Santa Claus] http://mathematica.stackexchange.com/questions/128741/house-of-santa-claus

The house of Santa Claus is an old German drawing game for small children. You have to draw a house in one line. You must not lift your pencil while drawing.

 $\color{red}{\text{You must not repeat a  ...

- asked by mrz (15 votes), answered by Dr. Wolfgang Hintze (9 votes)

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[how to get cell boundaries in the image] http://mathematica.stackexchange.com/questions/128596/how-to-get-cell-boundaries-in-the-image

I have a microscope image of some animal tissue and wish to get the contours for all the cells that are present in the image. the cells are connected to the neighbouring cells via these contours. At ...

- asked by Ali Hashmi (10 votes), answered by corey979 (13 votes)

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[Numerically solve the initial value problem for the 1-D wave equation] http://mathematica.stackexchange.com/questions/128516/numerically-solve-the-initial-value-problem-for-the-1-d-wave-equation

I want to solve the standard 1-dimensional wave equation \(y_{xx}=y_{tt}\) using NDSolve (for \(y(x,t)\)) with the following conditions:

cond1 = Piecewise[{{1 - Abs[x - 1], Abs[x - 1] < 1}, {0, Abs[x  ...

- asked by arcbloom (8 votes), answered by xzczd (7 votes)

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[Dataset Processing: efficient ways to clean and merge sets for Life Sciences] http://mathematica.stackexchange.com/questions/128519/dataset-processing-efficient-ways-to-clean-and-merge-sets-for-life-sciences

Dataset Processing (for Life Sciences)

Note: a related, but distinct task is posted here ID Swapping: Efficient use of a reference table to convert ID values.

A common task, at least for me, ...

- asked by SumNeuron (8 votes), answered by SumNeuron (5 votes)

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[Rotations of a number] http://mathematica.stackexchange.com/questions/128666/rotations-of-a-number

If we start with a number like 1234 and produce the following sum 1234 + 123 + 12 + 1 = 1370.

If we are given the 1370 can I retrieve the 1234? A similar question was migrated over to the Math.SE ...

- asked by bobbym (8 votes), answered by J. M. (6 votes)

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[What’s wrong with the Sum function?] http://mathematica.stackexchange.com/questions/128534/whats-wrong-with-the-sum-function

Here are the codes:

f[n_]:=Sum[1,{K,0,n},{M,0,n-K},{La,0,K},{Lb,0,n-K-M},{Lc,0,M}]//Simplify 
 
g[n_]:=Sum[1,{La,0,n},{Lb,0,n-La},{Lc,0,n-La-Lb},{K,La,n-Lb},{M,Lc,n-K-Lb}]//Simplify 
 
f[x]/.x->5

...

- asked by lamberto (7 votes), answered by Bob Hanlon (3 votes)

================================== Greatest hits from previous weeks: ==================================

[Creating legends for plots with multiple lines?] http://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines

So I have a graph with multiple lists, for e.g.

data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} 
 
 
If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have 
no way to generate a legend  ...

- asked by Eiyrioü von Kauyf (59 votes), answered by Jens (88 votes)

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[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file

I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with

 ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]],  ...

- asked by Matthew Leingang (85 votes), answered by Heike (74 votes)

================================== Can you answer these? ==================================

[Parallelizing code, any tips?] http://mathematica.stackexchange.com/questions/128905/parallelizing-code-any-tips

I have access to a Linux cluster and I’m trying to use Parallelize to run the above bellow faster, but whenever I try to place Parallelize in any other parts, besides the loop, where I think it may ...

- asked by Sergio Parreiras (2 votes)

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[Does Reduce have problems with greek symbols that lead to wrong results?] http://mathematica.stackexchange.com/questions/128965/does-reduce-have-problems-with-greek-symbols-that-lead-to-wrong-results

I call Reduce on the following simple system of inequalities

e = ((-4 + Sqrt[(-2 + )^2] + 3 ) Log[p] + 4  Log[])/(2 ); 
Reduce[e > 0 && 1 >  > 0 && 1 > p > 0  ...

- asked by klm (3 votes)

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[Full screen image in slideshow?] http://mathematica.stackexchange.com/questions/128875/full-screen-image-in-slideshow

Is it possible to make an image fill up and entire slide in a slideshow notebook so that there are no cell brackets or any white space around it at all (when viewed in presentation mode of course)?

- asked by M.R. (1 vote)