# All Questions

905 views

### Solving the Helmholtz equation in polar coordinates

I'm trying to (as a simple starter) find the solution to Helmholtz equation in polar coordinates -- I already know what it is and can derive it by hand, but just want to start here before asking ...
65 views

### Using NSolve in a function, selecting one indexed result and using it to plot another function containing a function containing the indexed result

I have a problem using the result pcvar[g] g e (0,1) in the plot cvar1. In the plot cvar I can use it. It must be somehow connected to clearing p in the definition of pcvar[g]. I am gratefull for any ...
3k views

### How to request financial data from Yahoo's YQL and Quandl?

How can I download historical data from Yahoo ? Although Mathematica's FinancialData function uses Yahoo it could be useful to have more control on how to retrieve data from Yahoo's YQL. Edit ...
100 views

### Graphing the sequence {$p_k$} = $\frac{c - a + dp_{k-1}}{b}$ [duplicate]

Graphing the sequence {$p_k$} = $\frac{c - a + dp_{k-1}}{b}$ I need to know how to graph this function where it automatically plugs in the previous term for $p_{k-1}$, the coefficients are of my ...
418 views

### Manipulating slots in a pure function

How does one manipulate the slot numbers in a pure function? Some trick with Evaluate or Hold? I'm aiming for something along ...
971 views

### Creating a Mathieu stability diagram

I am attempting to re-create a Mathieu stability diagram like the one shown here: I expected that I could use MathieuC to generate this graph by assuming that ...
85 views

### MapIndexed stops at levelspec 1 if only the index is passed?

If the function passed to MapIndexed references the first (or data) argument, the following performs as expected: ...
136 views

### Strange ImageFilter results

I am trying to perform some neighborhood analysis on an image, but ImageFilter seems to be interfering with the results outputted by the provided filtering function. Initialization Given the hue ...
402 views

### Is there a better way to add elements to a Graphics expression repeatedly?

Consider simple example where a set of points is generated and some are displayed. ...
148 views

### Using MousePosition on the entire screen - Screencast with Linux

In order to record animations more easily while using Mathematica on Linux, I would need to know how to get the position of three clicks. The following picture (main part generated by ...
141 views

### Path construction using Nearest shows ill behavior?

I have a dataSet that I'm trying to sort choosing a starting point and going to its nearest neighbor, and then to its nearest neighbor and so on. To do so, I've ...
95 views

### How to create list of delayed rules? [duplicate]

I am trying to make a ButtonBar that prints the name of the card in question. What I have so far is as follows: ...
285 views

### Function with a sharp resonance which Mathematica fails to integrate. Why?

I'm a new user of Mathematica and I'm trying to use it to calculate the collisional cross-section as a function of energy for a given potential and decay rate. I know that the resulting function ...
133 views

### How to show a general graphic (not a Plot) inside a Manipulate

I'm building a little interface, which consists only of a button, as you can see here: ...
245 views

### NMinimize holding problem

I have a function that I want to minimize numerically through an NMinimize command (because it's very complicated analytically). The minimizer call looks as follows: ...
43 views

### Verify “Type” of solution [duplicate]

I've written some Mathematica functions which allow the user to verify if a mathematical function has certain properties. What I'm basically doing is generating "random" functions in respect of ...
157 views

### Notebook keeps running when Solve for variable

This might be a simple question for the most of you, but I am very new to mathematica so please bear with me. I'll refer to the code below: ...
77 views

### List operation on specific elements [duplicate]

Let's consider two tables given by T1 = Table[{i,j,f1[i,j]},{i,0,2},{j,0,3}]; T2 = Table[{i,j,f2[i,j]},{i,0,2},{j,0,3}]; The functions ...
995 views

### What is the efficient way to code Successive Over-relaxation (SOR) method in Mathematica?

I have written a SOR method (SOR is this method) code using C-style procedural loops. However, I think there might be (much) better ways to achieve the same end in Mma avoiding these loops. So my ...
500 views

### Apply color function to matrix plot

I want to apply the following color rules to a large table of numbers. I have extracted a part of the table to use as an example. I would like to assign 5 different colors to 5 different ranges of ...
99 views

### Dynamic Syntax - Evaluate AppendTo as the second argument

I am attempting to Append a new value into my list paramMonitor whenever the value for B ...
198 views

### Simple subtraction question [duplicate]

I have two lists. a = {{2, 2}, {3, 3}, {4, 4}, {5, 5}}; b = {1, 1}; I want to subtract a from ...
451 views

### How to copy a function by value?

I need to change a function symbol multiple times by assigning another symbol to it, but when I'm trying to do that the symbols overwrite each other. I'm assuming this is because the assignment is by ...
166 views

### NIntegrate - WorkingPrecision

I am trying to NIntegrate this expression. It is very close to zero, and so gives all possible types of errors. More precisely, ...
171 views

### NDSolve - sampling for result during the computation

I am using NDSolve for a Langevin dynamics problem. I want to the know long term behaviour of my system ($t>1$) but it has to be simulated with very small time steps ($dt\sim 10^{-9}$). An example ...
111 views

### Ordered indices of a multiple product or sum

Given a summation like $$\sum_{1 \leq i_1 < i_2 < \dotsc < i_k \leq n} f(i_1, i_2, \dotsc , i_k)$$ how can the lists of indices be enumerated? For example, if $n=4$ then the possible lists ...
56 views

### Using SetDelayed wih SQLExecute

I want to create a reusable line of code that I can send a column, table name and criteria to match using the WHERE clause. ...
184 views

### Expressing a joint distribution for use in ContourPlot

I have $$X_1=T + W$$ $$X_2=2 T + 3 W$$ where $$W \sim N(3,5) \,\text{;}\,\, T \sim N(1,2)$$ and $$P(X=X_1)=P(X=X_2)=\tfrac{1}{2}$$ which I have awkwardly expressed as ...
104 views

### What is “ (Dialog) Input [ ] := ” after evaluating a cell?

I have done a time-consuming run and calculation. After many hours ( about 7 hours!), the black color which shows that the cell is evaluating, turn into gray and a strange text appears like this : ...
382 views

### Riffle and Partition

At some point I noticed that I was using Riffle and Partition together a lot. I would do things like ...
166 views

### Prevent package from being opened in a notebook interface

I have a package which I need to deploy in a client's environment. It has proprietary code and solutions that I need to protect from prying eyes and inquisitive minds. The forum has discussed much ...
125 views

### Scope of variables within a Manipulate expression [duplicate]

I have a problem in defining the local variables. I have this code: ...
100 views

### How do I count a number of primes(say smaller than N) that does not contain 5?

Title says it all. How do I count a number of primes(say smaller than N) that does not contain 5?
81 views

### nested series expansion

I have to invert the following matrix in which the functions U[t,x,y,r] and K[t,x,y,r] and all their derivatives are "small"; ...
228 views

### Kronecker delta notation

Is there an easier way to enter KroneckerDelta[n,m] in Mathematica? When I use the notation $\delta_{n,m}$, it won't work.
106 views

### Plotting the solutions of a system of differential equations on a simplex

I want to solve and plot the solutions of the following system on the triangle simplex: x'[t] == x[t]*(2*x[t] - 2) y'[t] == y[t]*(2*x[t]) z'[t] == z[t]*(2*x[t]) ...
54 views

### Substituting a function in the output

I have to calculate the derivatives of the function K defined in the code: ...
108 views

### Is there a way to use pause in Manipulate?

Is there a way to do any similar to Do[Print["Iteration...", j]; Pause[1], {j, 1, 6}] with Manipulate? (to show the ...
193 views

### Is there a PrimeQ whose accuracy guarantee you can adjust?

Say I have a list of a million integers each with a million digits, and I want a crude sieve to see which have a chance at being prime. Mathematica has a PrimeQ function, which appears to be slow ...
129 views

### Given two samples, how does LocationTest select its AutomaticTest?

How does LocationTest select its "AutomaticTest" when testing two samples? Background: A previous post poses a similar question ...
1k views

### Detecting patterns of black and white stones on a 2D board

I'm writing a program to play a game of Pente, and I'm struggling with the following question: What's the best way to detect patterns on a two-dimensional board? For example, in Pente a pair of ...
130 views

### ListPlot, PlotMarker -> y value [duplicate]

at first sorry if this question is already answered. I would like to display y value as plot marker in listplot ...
642 views

### DSolve will not apply assumption m ∈ Integers

I am trying to solve a linear second order ODE using DSolve which involves an arbitrary integer m. ...
426 views

### Extracting financial indicator data from trading chart

How can the data of the directional movement index below be extracted from this chart? It seems to be embedded in some kind of dynamic module. ...
253 views

### How can I find a root of my transcendental equation near a certain point?

What function could I use to solve this equation for x: E^(-x^2) = 1 - Cos[x] I tried Solve, ...
295 views

### StringReplace, ReplaceAll and Rule interact in a bizarre way

I have the following pair of things: ClearAll[foo, labeledFoo]; labeledFoo = {"FooBarBazQuux", foo}; This works like you'd expect: ...
85 views

### How write this Function with many arguments? [duplicate]

F[x1_,x2_,...,x99_]:=expr How to write this Function in mathematica whithout complete write it?
162 views

### Solve a system of M equations without specifying M

This post has been edited heavily in response to the comments: my initial question was very confusing. I am trying to write my game-theoretic model in Wolfram Language. There is only one remaining ...