All Questions

3
votes
2answers
149 views

I'm trying to make an internet radio alarm clock

I'm trying to make an alarm clock which opens a website. I have something which works but it is imprecise and generally quite ugly ...
3
votes
1answer
88 views

An efficient way to compare two matrices

I have two matrices mat1 and mat2, both are results from different algorithms that are supposed to calculate the same result. The nmax is around 300, the q varies from 0.001 to 1. ...
4
votes
0answers
34 views

FindSequenceFunction for sum of hypergeometric terms

Mathematica's built-in function FindSequenceFunction is quite good at recognizing hypergeometric terms, i.e. terms $c_k$ for which $c_{k+1}/c_k$ is a rational ...
1
vote
1answer
62 views

How can I simplify this implicit equation to an explicit equation

How can I simplify this implicit equation to an explicit equation: Tan[5 y/12] - (7 y/((x)^2 + (y)^2 - (3.5)^2)) == 0 i.e: $y=f(x)$ where $y$ is a explicit ...
1
vote
1answer
98 views

Basis for the intersection of vector spaces

The MuPAD Notebook Interface provides the linalg::intBasis function: http://www.mathworks.com/help/symbolic/mupad_ref/linalg-intbasis.html How can I get the same ...
1
vote
2answers
30 views

Summing over n variables [duplicate]

I am currently trying to create a function taht will sum over n variables, but I don't really know how ot implement it. It should look like this: $f[n]=\left(\frac{1}{6}\right)^n \sum _{x_1=1}^6\sum ...
0
votes
0answers
32 views

Confusing memoization behavior — caching a function that returns a function

Here is a simplified version of what I am trying to do: ...
0
votes
0answers
32 views

Speed up numerical optimization (for plotting and solving)?

Briefly speaking, I want to plot a function PIfun[], which its value is based on numerical optimization using NMaximize. It ...
9
votes
3answers
256 views

Generating hatched filling using Region functionality

Before v.10 came out there were several Q&A on generating hatched filling for Plot, ListPlot etc. In v.10 we have new ...
1
vote
0answers
38 views

Findfit doesn't provide reasonable results when fitting a complex function [on hold]

I am trying to fit some data using the function which contains two parameters (a, b) as described below. Hope to determine the a, b that best fit the data. My input is: ...
0
votes
0answers
27 views

Implementing normalization/rescalement from a Tutorial

I'm trying to implement a rescale/normalization as is described in here by mathematical expressions in page 10, and code in the top part of page 16. The notebook is also available here. When I try to ...
1
vote
1answer
61 views

Obtaining probability density function from a cumulative distribution function

I have some difficult times to obtain the density function of ...
1
vote
1answer
98 views

Solving systems of equations

So I have a set of equations like 12 of them but 13 variables. However I would like to find the numerical value of the roots for the maximum value of a particular variable. I don't know how to do that ...
4
votes
2answers
98 views

Plotting two functions in one graph, with different value ranges [on hold]

Plot[2x, {x,0,4}]; Plot[x^2, {x,4,8}]; How do I merge these two graphs into one?
5
votes
4answers
199 views

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

I have a following matrix ...
1
vote
1answer
69 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 [on hold]

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
92 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 [on hold]

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 [on hold]

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
152 views

Graph smoothing keeping vertices fixed?

Context Given a Graph like this one: ...
2
votes
0answers
37 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 [on hold]

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 ...
0
votes
1answer
59 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
65 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
92 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: ...
19
votes
2answers
405 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
32 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 [on hold]

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
34 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
39 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
25 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: ...

15 30 50 per page