All Questions

5
votes
4answers
200 views

How to extract a part of matrix satisfying certain condition(s)

I have a following matrix ...
1
vote
1answer
70 views

Filling between ParametricPlot and Plot

There are some similar questions: (1) (2) have been ask, but I think this is a different one. If we have a ParametricPlot and a ...
-2
votes
0answers
37 views

How dose solve this equation for a group of x,y, slope of shape [closed]

This is equation of an ellipse. 5*Y-12*ARCTAN(7*Y/X^2+Y^2-(3.5)^2)=0 OR TAN(5*Y/12)-7*Y/[X^2+Y^2-(3.5)^2] how solve this equation for a group of x,y? (Discretization of shape) How to solve for ...
4
votes
2answers
93 views

Selecting y-values from xy coordinate grid

Suppose I have a table, u, which is created as follows: ...
3
votes
1answer
51 views

How to speed up Min of DateObjects?

I'm in version 10.0.1 using a Dataset to do some plots and things. For one of the plots I need to get the minimum date of a some filtered set of the ...
-1
votes
0answers
33 views

Lost all spaces in a paragraph [closed]

I accidentally pressed the convert-cell to something, don't even know to what... and then found that most spaces in document were lost in that paragraph. I cannot get them back. Please let me know ...
0
votes
0answers
48 views

Sundaram's Matrix in Mathematica [closed]

How to Implement the Sundaram's Sieve in Mathematica? If a number is in the Sundaram's matrix I wanted to know the row and column.
10
votes
2answers
155 views

Graph smoothing keeping vertices fixed?

Context Given a Graph like this one: ...
2
votes
0answers
39 views

Mathematica AppData folder is taking up too much space

I recently made a small app that I had issues with. I'm pretty sure it ended up being because of all the curated data to load. My problem now is that under the Windows 8.1 folder ...
0
votes
0answers
50 views

Juxtapose 2D and 3D plots [closed]

Can 2D and 3D plots be combined so that the 2D plot is the bottom surface of the 3D plot boundary? More on combining 2d and 3d plots Here are some questions here that might make this question a ...
1
vote
1answer
60 views

NDSolve with a constant

I have a simple differential equation like this s = NDSolve[{y'[x] == A y[x] Cos[x + y[x]], y[0] == 1}, y, {x, 0, 30}] where $A$ is a constant. Mathematica gives ...
1
vote
0answers
38 views

How to build a constant Graphics object

I'm making an animation with Manipulate for a representation. The code looks like this ...
5
votes
0answers
66 views

Second order differential equation with boundary conditions solving repeatedly

I want to solve a second order differential equation in the interval[-1:1], which does not have a analytic solution, \begin{eqnarray} y''(x) &=& k \phi^2(x)y(x) \\ \phi(x) &=& ...
1
vote
0answers
28 views

Control size of formula in a gridbox [duplicate]

When I enter a multi-line formula, I always use a gridbox. But I find that the size of formula in each box is not appropriate. For example, when I enter a compound formula containing fraction or ...
0
votes
0answers
10 views

OpenCL_error by ImageSize option

Unable to unload memory problem. The example is in OpenCLFractalRender3D
5
votes
2answers
171 views

Unexpected Integration Constant [on hold]

Why does this integration Integrate[15-30x+6x^2-1/(x+5),x] return 700 as integration constant? If we make a slight modification ...
2
votes
0answers
26 views

Automatically discover the class of an arbitrary matrix

In Wolfram|Alpha it is possible to discover some specific classes to which a matrix belongs. For instance, typing this in Wolfram|Alpha ...
2
votes
0answers
37 views

OpenCL_result not the same as that in the example-Julia

My system is "Windows-x86-64", Mathematica version is 10.0, my card is GTX860M When I'm trying this example, my result is not the same like that in the example. ...
0
votes
0answers
23 views

Solving/simplifying a trig function [migrated]

Given: $\tan\:a=\frac{5}{12}$ and $a\in QIII$ $\csc\:B=-\frac{5}{4},\:\cos\:B>0$ $\cos\:\theta =-\frac{8}{17},\:\frac{\pi }{2}<\theta <\pi $ Solve: ...
0
votes
0answers
25 views

Solving/simplifying a trig expression [migrated]

My problem sheet says that $\tan a= 5/12$ and $a \in {\rm Q\,III}$ ($a$'s in quadrant III). Using this information, I am to solve/simplify the expression $\quad \quad \cos\left(\frac{1}{2}a\right)$ ...
4
votes
3answers
124 views

Determine if a variable appears in an expression or not?

Consider an arbitrary expression expr. This expression may contain arbitrary data, like integers, variables, implicit functions etc. Now, I would like to determine ...
2
votes
0answers
50 views

Can't find the limit of this complicated expression

Here is the limit I am trying to calculate ...
3
votes
1answer
56 views

FreeQ and arguments of Hypergeometric2F1

I was trying to use FreeQ to test for the presence of Hypergeometric2F1 functions in my expressions. I encountered the following ...
2
votes
0answers
54 views

Derivatives of functions with arbitrary number of variables?

I am trying to define a function f[x1,x2,...,xn] with n integer but not specified. And then I would like this funktion to behave ...
3
votes
0answers
93 views

What is the causing these colored marks to appear in my Mathematica notebook?

I'm particularly annoyed with the black ovals that occasionally obscure parts of the input as I'm typing: I have also observed the appearance of rectangular blue marks with similar behavior: ...
20
votes
2answers
417 views

Poets of the 19th century

...
4
votes
2answers
94 views

Weird behavior of conditions when using OptionsPattern and OptionValue

I'm trying to define a function that is evaluated differently depending on its options. This code ...
0
votes
1answer
33 views

AutoGeneratedPackage Formatting

If you do Ctrl+Shift+o you open an option inspector. And then you can enable ...
1
vote
0answers
39 views

Can Listplot output data to an image whilst leaving axes and labels as vectors? [duplicate]

Question: Can Listplot be set to render the data as an image whilst leaving axes and labels as vectors when saved as a PDF? Context: I have around 100,000 points in my listplot which when saved to a ...
0
votes
0answers
66 views

Mathematica 10 is shuttingdown many times [closed]

I run mathematica 10 on mac osx 10.9. It shutdown many times. I do not understand what happen. What is the problem. Any clarification?
0
votes
2answers
51 views

A constraint to RandomReal for sum of numbers equal to arbitrary n

I want to generate some random numbers but respect a constraint. So I use RandomReal[{0,1},N,WorkingPrecision -> 2] I want to fix a constraint in order ...
3
votes
0answers
49 views

How to derive SinglePredictionBands from a NonlinearModelFit model

I have found NonlinearModelFit to be extremely useful in my work. Here I have fit 4 points to a function and am being asked to explain how the 95% SinglePredictionBands associated with the plot below ...
0
votes
0answers
35 views

Copying an “upright” fraction and pasting it gives a “flattened” fraction

I use Mathematica 10 on OSX Yosemite I copied (command+C) an "upright" fraction like in an input line and pasted (command+V) it in another. But, it gave a "flattened" fraction like . Is there a way ...
2
votes
3answers
89 views

plotting two Error List Plots in one

I made two ErrorListPlots ...
1
vote
0answers
40 views

Bug? malloc munmap_chunk: Assertion failed

I run a mathematica script on a Linux system and after two days it dies with the error message MathKernel: malloc.c:3546: munmap_chunk: Assertion `ret == 0' failed. Aborted There should be ...
0
votes
0answers
26 views

Mathematica Integrate implicit assumptions returns a function not defined in some points while NIntegrate performs integration safely

Hi guys i'm performing a standard integration with mathematica routine Integrate, the function i'm integrating is the following: ...
2
votes
4answers
316 views

Solving puzzles with Mathematica

I would like to be able to solve logic puzzles such as the one described here using Mathematica. I have copied & pasted the listed example below to save on jumping about with hyperlinks: The ...
1
vote
1answer
86 views

Trouble with Fourier transform of Exp[-Sqrt[x]]

First time trying to do something "real" in Mathematica, I am having trouble getting it to calculate this Fourier transform. It runs for a long time, then just prints the input expression. ...
0
votes
0answers
20 views

NMinimize outside the feasible region

I got the following minimization problem. I get a solution if I set constraints1 := L.x >= y; and eliminate constraint 2 from my set of constraints. So ...
4
votes
3answers
97 views

A Product function for matrix products

I would like to use an equivalent of the product-function in mathematica, but where instead of multiplying numbers I multiply matrices?
0
votes
2answers
39 views

Convert imaginary exponentials to goniometric expressions

Can I force mathematica to re-express something like $$\left\{\frac{1}{2}i\left(\frac{1}{16} e^{-2 i (\alpha (1)+4 \alpha (2))} \left(-1+e^{8 i \alpha (2)}\right) \text{d$\alpha $}(1) \left(2 \left(2 ...
2
votes
4answers
129 views

Problem in finding the numerical maximum

I need to find the numerical maxima of the function $$i(s)=\bigg[ \frac{\sin{50\pi (\cos s+1)}}{\sin{10\pi (\cos s+1)}} \bigg] ^2$$ Or in the mathematica input form: ...
0
votes
0answers
57 views

What's the wrong when I use the BodePlot?

I want to plot this Butterworth filter's TransferFunction: ...
0
votes
0answers
57 views

Birch clustering in Mathematica

I want to implement birch clustering in Mathematica. MAthematica only has 4 methods of clustering, is there any implementation for Birch clustering? Birch clustering is much faster than K means ...
2
votes
0answers
61 views

Distance Time Warp (DTW) function implementation in mathematica

The DTW (Distance time warp) is given here http://en.wikipedia.org/wiki/Dynamic_time_warping There is an implementation of DTW in R as well as MATLAB. However i am unable to find something for DTW in ...
1
vote
0answers
41 views

Understanding the order of applying Rule to expression [closed]

I am a little confused about: In what order is a Rule tried to apply to an expression? In a depth-first order or otherwise? For example, ...
3
votes
0answers
46 views

RawArray crashes the kernel

RawArray seems to crash the kernel on my machine RawArray["Byte", {}] Is this a bug? Any insights why this happens? My system: version 10.01 on Mac OS X 10.0 ...
-2
votes
1answer
46 views

Why is it so complicated to simplify a complex conjugate? [closed]

My question is very simple. I would like to multiply a complex number by its conjugate. Unfortunately, this seems to be extremely complicated in Mathematica. Consider the very basic example: ...
1
vote
2answers
50 views

Assigning to the “local” version of a symbol

Compare Manipulate[c[1] = 1; c[1], {c[1], 0, 1}] with Manipulate[Do[c[i] = 1, {i, 1}]; c[1], {c[1], 0, 1}] The first case ...
-2
votes
0answers
52 views

Finding the domain of this trigonometric function [migrated]

how can I find the domain of this function? f(x) = (xsin(x) + cos(x) / 1 - cos(x)) + (|X| - 2 / x^2 -4) I assume we don't want the dominator to be zero so f(x)1 ...

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