0
votes
2answers
93 views

Setting CheckboxBar defaults under Manipulate

How is the default for the checkboxes created by CheckboxBar in a Manipulate set to be checked instead of unchecked? (The ...
1
vote
2answers
118 views

Error Trapping Complex Infinity Error due to Divide by Zero in Manipulate

I want to use a Manipulate that has two controllers that end up as a difference in the denominator of an expression. It is easy enough to set up the initial ...
1
vote
1answer
73 views

Moving the start of a graph to the right, finding maxima in an oscillator

I have the following code written to simulate a driven damped oscillator ...
0
votes
1answer
70 views

How to compile gather [duplicate]

First question,How to Compile this? gather[data_]:=Gather[data, Mod[#1, 3] == Mod[#2, 3] &] I dont know why this is wrong. ...
0
votes
1answer
349 views

Trying to solve a transcendental equation involving bessel functions

I've never used Mathematica before and am trying to numerically solve equation (12) from this paper: http://arxiv.org/abs/hep-ph/9907218v2. Ideally I'd be able to find the smallest value of $x_{n\nu}$ ...
19
votes
2answers
647 views

How to make a curve selectable from a scaned image and convert it to a list of coordinates

I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ...
2
votes
2answers
175 views

Set PointSize to pixel size

I have a set of 1million 2D points and I would like to produce an image 200x200 pixels where each point will have the size of a pixel (no more). Additionally each point may repeats several times so I ...
1
vote
0answers
107 views

What are the hidden specifications for FindRoot

The Help page of FindRoot says: "by default, FindRoot uses Newton's method (Newton-Raphson) to solve a nonlinear system" (or a nonlinear equation I ...
3
votes
3answers
281 views

Data Table Manipulation

Suppose that I have the following ...
2
votes
1answer
89 views

SQL Queries with the Table function

Given the following connection to an SQL query works but the data comes out wrong: ...
0
votes
1answer
95 views

How do I apply a rule to every element in a matrix? [closed]

I need to apply a set of rules (I used Which) to every element in a matrix, but the rules are dependent on the position [[i, j]] ...
3
votes
3answers
175 views

FindRoot constrained to maximum

I am using FindRoot to find the local maximum op some function, by examining where its derivative is zero. However, keeping the starting value the same, sometimes ...
2
votes
1answer
103 views

Accessing Draw Tools objects with notebook commands

In a notebook I would like to be able to access and modify the properties of draw tools objects after I've drawn them on a graph by hand. For example, if make a plot and, with draw tools, make a ...
0
votes
0answers
16 views

?AspectRatio? setting to obtain equal length pr pixel on all axes [duplicate]

Like these does: Show[Graphics[Rectangle[{2, 1}, {15, 2}]]] ParametricPlot[{t,t t},{t,0,2}] how do I create a Plot[] with ...
1
vote
0answers
72 views

Mathematica exit when calling plot. Bug?

I'm currently studing the behaviour of some integral for which I cant find an analytic solution. As this function depend on a vector on the unit sphere, I first defined it with 3 parameters before ...
2
votes
1answer
233 views

How to use the function ImageCorrelate? [closed]

I am a beginner in using Mathematica, know little about optics. However, I would like to know how to understand the function ImageCorrelate, since the ...
1
vote
1answer
305 views

Why does Mathematice dislike my boundary condition in NDSolve?

im trying to solve a PDE-System, with the "periodic boundary condition" c[t,0]==4*c[t,2pi] But mathenmatica says: NDSolve::bcedge: "Boundary condition ...
6
votes
3answers
422 views

Mathematica style (drawing cubes)

I wanted to draw (lattice-aligned) unit cubes inside a sphere with a given radius centered on the origin, so I wrote this program: ...
2
votes
2answers
507 views

Solving simultaneous exponential equations

In[1]: Solve[{(1 + k)^n == 0.6, (1 + k)^(n + 1) == 0.3}, {n, k}] Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; ...
4
votes
2answers
426 views

How to transform transfer functions into differential equations?

is there a way with Mathematica to transform transferfunctions (Laplace) into differential equations? Let's say I have the transfer function $\frac{Y(s)}{U(s)}=\text{Kp} \left(\frac{1}{s ...
0
votes
0answers
34 views

Using Map with functions that take a parameter [duplicate]

I have a list l={{0, 0, 0, 3}, {0, 0, 0, 3}, {0, 0, 1, 2}} And I would like to obtain the number of zeros in each sublist: ...
2
votes
2answers
452 views

Removing trailing zeros from a list

If I have a list like list1={2334.,342.,0.,0.,2322.,0.,0.,0.,0.,,,,,,}; it's easy to remove to trailing blanks with ...
1
vote
1answer
214 views

Numerical Instability?

Current Status Please skip ahead to Update 2: the key questions are now: 1/ Why does Mma generally fail to find the minimum for a well behaved function when the function does not have infinite ...
3
votes
0answers
98 views

Deciding whether a semi-algebraic set is empty. Which command is best?

[Update] I was able to prove that the "larger" set $ 1\ge x \ge y,w \ge 0$ and $p(x,y,w)>0 $ is empty with another computer algebra system in my slow laptop in few minutes but in Mathematica even ...
1
vote
2answers
76 views

CDF of TransformedDistribution Not Returned And No Error Message Produced

I am unable to get Mathematica to return the CDF of a distribution produced by TransformedDistribution. It "executes" for 6 hours on my machine and then returns a blank plot. Could someone execute the ...
-1
votes
1answer
68 views

How to fit one parametric array to another numerical array?

I have two arrays of length n. One of them is obtained by experiment, so every element of the array is a number. The other array is parametric, each element is a ...
1
vote
1answer
64 views

ReadList error with negative very small numbers

When I try to import data with ReadList from a file containing very small numbers (~10^-318), positive data is handled well, ...
0
votes
1answer
101 views

Writing equations from Mathematica in Matlab [duplicate]

I would like to use mathematical equations directly in Matlab. I found one thread describing about a built in Matlab file i.e. ToMatlab.m. I am able to download this file, however, I could n't able to ...
0
votes
1answer
53 views

Replacing whole strings

I imported a text and seperated al words by using StringCases. After this I would like to manipulate the text, for example to replace all singular verbs to plural. ...
4
votes
2answers
126 views

Values (or positions) of array row elements within a specified number of positions from target value

I have the need to collect values from the rows of rectangular arrays of arbitrary precision integers, given a target element value and allowed "distance" (positions +/- within the row from found ...
4
votes
1answer
77 views

OpenCLLink eating up all host memory

I am calling lots of OpenCL functions from Mathematica. The problem is that the memory the kernel uses grows and grows until the RAM is fully occupied. I have created a small piece of code to ...
2
votes
0answers
77 views

Front End - Bug in Edit->Find?

As a beginner I make notes in my notebooks on what I am learning as I go along, and I have also referenced the help files by pasting hyperlinks from them - this seems to break the Find function. Is ...
0
votes
1answer
398 views

Plot 3D density

I have data that is in four columns. The x y and z are just the coordinates and the fourth is my data. This is not a function. This is electron density in a copper cell and I'm trying to display it ...
2
votes
1answer
82 views

Why can I edit only one character of the output of a Dynamic expression?

Try this: DynamicModule[{foo = \[Placeholder]}, foo] Note how we're able to edit the placeholder in the output, e.g. replace it with 42: ...
1
vote
1answer
149 views

How to get the dimensions of a rectangle?

Suppose I create a Rectangle of dimensions 1 and 3. Is there any function in Mathematica that I can use to recover the dimensions of the original rectangle? If there is no such a function, is there a ...
0
votes
1answer
192 views

Taking the time derivative of a function with more than one variable depending on t? [closed]

Yeah, I was wondering if it was possible ? I have a function which have different variables depending on time, like: $$\frac{d}{dt}mr^{2}\dot{\phi}$$ In this case both $r$, being a length, depends ...
3
votes
4answers
540 views

More elegant way

I read ReplaceOrRemoveInvalidOrMissingData Mathematica documentation, and I tried to apply the same approach to my dataset. I've got two problems, but one is only a style problem! There is one more ...
2
votes
2answers
247 views

Change Meta-Information “Title” of PDF file in Export

Whenever I export a PDF file in Mathematica with the Export command, the meta-info of the pdf file will have the title as "Temporary Clipboard 0". I want to change the title. But using: ...
5
votes
1answer
462 views

Asymptotic expansion

I wanted to expand a function of $x$ about $x=\infty$ and see its coefficients as a function of the parameters $m,n,q,y$ and I wrote this - but it didn't work! It gave me back a very complicated ...
4
votes
3answers
219 views

Increasing the precision of a calculation

Clearly I have misunderstood how to do this: I seem unable to understand how to get more digits out of a calculation and I can't see why - the following piece of code illustrates the issue. ...
3
votes
1answer
261 views

project moving point onto a line

The following code displays three solutions to the logistic ODE with an animated points that follow the solutions.. My goal is to project the solutions on to a vertical phase line. I need to be able ...
2
votes
1answer
108 views

how to distinguish clockwise from counterclockwise rotation

I need to distiguish the true rotation of a vector (time dependent, solution of a system of two coupled differential equation) respect a fixed vector. As showed in the follow,neither ...
0
votes
1answer
176 views

Visualize fixed points and stable points in 4D

I have a list of 4 dimensional data points which are sum to one and always positive. These points are the fixed points of the 4 dimensional nonlinear ODE. I also found the stable points of the system ...
0
votes
2answers
111 views

Distributing value of variable to specific kernel

I want to distribute the value of a variable to a specific kernel in a parallel computing setup. Using DistributeDefinitions of course does the job, but it ...
6
votes
2answers
439 views

Correct fourier scaling and high-resolution frequency identification

I have a dataset of amplitude versus time $(t,A(t))$ and I need to extract the dominant frequency and amplitude, and also get the amplitude at one other specific frequency. My data looks like this: ...
0
votes
1answer
63 views

inverting this equation [closed]

I'm trying to inverse this equation Z = X + X^2 / 2 but couldn't wrap up my head around it. If anyone can provide a step by step solution to this it will be ...
3
votes
1answer
397 views

ReadList with header and foot lines

I want to do some large data analysis, and i want to be able to import files in a fast way. I tried Import, but it is quite slow; ReadList takes half the time. This is the code I was using: ...
9
votes
1answer
403 views

Compile function which calls other functions to C

I have a function which calls other functions and I would like to compile it to C code. For example: ...
5
votes
4answers
2k views

“do … while” loop equivalent in Mathematica [closed]

Have I missed something or is there no built-in which mimics the behaviour of do ... while loop? I am looking for a construct that evaluates procedure once and ...
5
votes
1answer
388 views

Mathematica-To-MATLAB Dictionary!

Is there a dictionary to translate Mathematica functions and commands to MATLAB?

15 30 50 per page