# All Questions

0answers
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### DE Solver/ FindRoot

Here is my code, It is all correct with no error messages. However, it is only finding one root but I want it to find the first 5 roots (first 5 eigenvalues of this ODE). So I am wondering how I can ...
1answer
184 views

### Why does a variable become real when using the second argument of Dynamic?

Version 9, on Windows 7. Please compare these 2 very simple examples Manipulate[ x, Row[{Manipulator[Dynamic[x], {0, 10, 1/100}]}], {{x, 1}, None} ] and ...
0answers
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### Why does one of my Manipulate integer variables get turned into a real?

I'm developing code for manipulating graphs. Spot the difference in the 2 Manipulates below: ...
0answers
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### Fast way of finding position of Interval containing an Integer

I have a large list (about 2.2 million) of pairs of integers. Each pair defines an Interval[{}]. Given some integer x, I need to ...
1answer
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I evaluate ...
2answers
22 views

### Forming a list out of a solution

I have two lists: listcs that depends on a variable y, and listex, which is a list of ...
0answers
8 views

### Time Varying Payoffs?

I'm trying to write some code that will return the final value of an annuity whose monthly payouts may or may not be constant each month. Right now I have working code for constant payments, but I'm ...
1answer
11 views

### is there a way to construct a pattern that would trigger when an expression is used as a held/unevaluated in some form?

For example, consider the following code f[x_] := (Print["evaluated f"]; workWith[x]); We use it, then f evaluates: ...
0answers
30 views

### Repeatedly evaluating a function

I'm relatively new to Mathematica, so forgive me if this is overly simple. I'm trying to evaluate a function several times using different integer values for one of the parameters each time and then ...
1answer
18 views

I'm new with Mathematica, I tried to define C[n_]:=Sum[c[i],{i,1,n}] but I get $Failed. Not sure what am I doing wrong here... Thanks for any help. 5answers 372 views ### How to save Manipulate bookmarks permanently? I would like to save current Manipulate parameter values to load them again later. Bookmarks (previously discussed here and here) work fine until the cell is ... 0answers 14 views ### Hide MathKernel Tab on Taskbar when using C++ I am connecting to MathKernel.exe using C++ via MathLink on Windows. Hence, to create the link, this is what I use: ... 2answers 59 views ### NDsolve with variable end-point I want to plot the solution a coupled ODEs as a function of the end point only. Mathematica code: ... 1answer 49 views ### Computing Smith Normal form of a matrix with mod p coefficients I would like to compute the Smith Normal form of a matrix with coefficients in GF(p). In particular, I am interested in GF(2). I have used the Smith normal form packages for integer and polynomial ... 0answers 14 views ### Wavelet Decomposition using daubechies I am trying to use wavelet decomposition technique to extract the fundamental frequency of a signal using simulink. I passed my signal through buffer > DWT > IDWT > unbuffer but there is a delay of ... 1answer 34 views ### MapThread over a nested list This may be a simple question. Please close it if it is already answered. I have a nested list kr = {{35, 32, 27, 20}, {36, 33, 28, 21}, {37, 34, 29, 22}} I ... 1answer 74 views ### Polynomial GCD over a ring (with composite characteristic) I'd like to implement the "Franklin-Reiter Related Message Attack" (see section 4.3 of Boneh's paper). As part of the implementation, I require to compute the GCD of two polynomials over ... 1answer 36 views ### Extension of harmonic number to the real domain What is exactly the domain of validity of the identity: Sum[1/(k + j - 1), {j, 1, i}] == HarmonicNumber[k - 1 + i] - HarmonicNumber[k - 1] when ... 1answer 30 views ### Conditional clustering of elements I have a long list like: ... 1answer 84 views ### Fourier Transform Help I'm trying to do a Fourier Transform of the following Data, but I'm completely stuck. Here's what I've done so far: ... 1answer 47 views ### How to apply RootLocusPlot corectly I have to analyze the complex regions of variable c which is define obtained with InverseLaplace help in the form ... 2answers 147 views ### How can I improve Do loop? I have very large input of time series data (over 30000 observations) that look like as follows: ... 0answers 40 views ### A blank result with Integrate and NIntegrate [on hold] Can someone kindly help with this integral? Why is Mathematica unable to even do a numerical integration on this? ... 1answer 221 views ### What type of solver does Mathematica use in LinearSolve I have a question regarding linear equation solvers. For a specific 9x9 diagonal matrix, every method I tried in C++ (Gaus, GCC, BICGTAB ) wouldn't work, although these methods would work fine for ... 0answers 33 views ### Performing a simple symbolic coordinate transformation? I am making the effort to start using Mathematica for my research because my derivations just get too unwieldy at times. I've been getting frustrated at step 1. This is my problem: I have some ... 0answers 75 views ### NDSolve example - analytical vs numerical solution. How to specify initial conditions? So, I have the following equation: y[t]^-3 == w^2 y[t]/t^2 + y''[t] where w^2 = (t0 k0)^2. Analytic solution is easy to ... 0answers 25 views ### Discrepancy Assumptions$ = and Assumptions -> [on hold]

Why do global assumptions not apply to the argument of the cosine function? Example: I tried ...
0answers
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### A design of abstract data structures: How robust is the presented design?

I know that this question has been asked many times. This is my take at it. Ideas are not mine, they are borrowed from many posts on this site. Below is the core of the best setup that I came up with ...
0answers
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### Mapping the imaginary axis of the complex (s) plane

In this problem is very difficult to analyze the roots s. Firstly I thought that the problem is in precision, but I am not sure. The criterion which I want to obtain is that one of these roots has a ...
0answers
33 views

### Approximate to the speed of Build-In functions

In Mathematica, there is a function PowerMod[a,b,m], which computes a^b mod m. I will concern only this case: ...
1answer
24 views

### Start indexing at 0 for RSolve without giving an initial value

I am trying to use RSolve with indexing beginning at 0. Whenever I enter a basic command such as to solve a difference equation such as $a_{n} = 2a_{n-1} + 1$: ...
7answers
1k views

### Simpler input for the new unit support

I've been playing with the new unit support in Mathematica 9. It seems very useful, but the syntax is very verbose. Instead of typing: ...
2answers
54 views

### 2D Cellular Automaton: Initial conditions

I'm trying to write in Mathematica for a 20x20 grid, with 100 colours, with 4 neighbours. I want the initial conditions to be a 20x20 matrix consisting mainly of zeros. ...
1answer
121 views

### Is it possible to give the closed-form of the stiffness matrix of triangular prism element?

Suppose the vertices of triangular prism are 1, 2, 3 (bottom triangle), 4, 5, 6 (top triangle), the coordinates of the vertices are $$(x_i, y_i, z_i), i=1,2,3,4,5,6.$$ We can write the stiffness ...
2answers
32 views

### Filter through list and lump data [duplicate]

I have a very large data set (around 3000) that looks like: ...
0answers
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### Integrate double definite integral [duplicate]

I am trying to evaluate an integral numerically and plot its result. My mathematica code is: ...
1answer
35 views

### Invariant error plot for an arbitray system of ODE

i try to use InvariantErrorPlot command for a generic system of ODE but i find only example with pre-building equations from Mathematica Packages. This is one of ...
1answer
351 views

### What does ImageSize -> 1 -> 1 mean?

On the page http://www.wolfram.com/language/gallery/blur-faces-in-an-image/ the example code has ImageSize -> 1 -> 1. I am unfamiliar with this chaining of ...
2answers
216 views

### What does rule 30 mean in this example? [on hold]

This starts with the list given, then evolves rule 30 for four steps. ...
1answer
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### Wait / sleep miliseconds

Is there any way to make Mathematica stop for some miliseconds? I know about the Pause[] but it seems it only works with seconds.
2answers
105 views

### Parametric plot of multiple graphs on the same axes

I'm trying to plot on a single axes system multiple graphs but ran into a problem when tryinf to label my graphs. Here's what I've used so far Mathematica code: ...
1answer
65 views

### Code Performance Tuning

The following code takes over 4 seconds to run. Any one has suggestions to make the expressions for qf, phi, ...
1answer
275 views

### GraphPath: *all* shortest paths for 2 vertices, edge lengths negative

Mathematica uses Bellman-Ford to find a shortest path between two vertices when the edge lengths are negative: ...
1answer
55 views

### Combine Plots into a single non-rasterized Graphic with no spacing

Suppose that I have two plots, pl1 and pl2: ...
1answer
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### Export resuts to excel

I have the following problem solved in Mathematica ...
2answers
250 views

### How to match a cyclically repeating sequence?

I have run across several times recently where I must match a sequence that is cyclically repeating. For example, with the sequence, Sequence[a, b, c] how would ...
0answers
39 views

### Descriptive interface for data analysis workflow [on hold]

In exploratory data analysis, data cleaning and structuring tasks, it's convenient to temporarily apply functions like Dimensions, Depth, (and also TableForm, MatrixPlot, etc) as informative checks to ...
1answer
132 views

I evaluate ...
0answers
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### I need to cite the same reference several times. Mathematica citation manager messes up

Mathematica cannot seem to properly number citations when there are several citations to the same reference. Is there some trick to make this work?
1answer
60 views

### How to make an arbitrary number of plots have different labels/colors/etc?

I'm sorry but I'm not sure how to phrase this question well. Frequently I have a function that produces and returns a Plot[] or array of Plot[]'s, which I can then display with Show[], or combine with ...

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