All Questions

19 views

Symbolic and numeric limit disagreeing on branch cut of ArcTan

Investigating comments to my previous question lead me to the following problem: ...
21 views

How can I reduce a directed graph to only its “junctions”?

I'd like to take a directed graph, e.g. ...
29 views

How to use the built-in function GraphElementData

Very surprise to me.I found this is a built-in function but it is undocumented.Such as this answer's "CurvedArc" and ...
54 views

Different options for ResamplingMethod specification

Is there an option for ResamplingMethod (or any other practical way) for specifying different behaviours of the interpolation, depending on, for instance, closest dates (on the ...
14 views

diophantine linear equation with condition on the sum of coefficients

I am trying to solve the following diophantine equation x*a + y*b == c where a,b,c are integers and the absolute value of their sums is, for instance, 4. Then I ...
65 views

Undershoot/Overshoot Method for this differential equation?

I have tried to solve this equation for some weeks and I am not capable. I have read in articles that it is easy with an undershoot/overshoot method, but I don't know how to do it. ...
28 views

Plotting the complement of a graph without changing the name of the vertices

I have a graph in the form {Dog -> Apple, Apple -> Screwdriver}, I used to plot a graph in the following way: ...
85 views

Integrate and NIntegrate disagreeing over branch cut of Sqrt?

Bug introduced after v8.0.4 and before v9.0.1, and persisting through v10.4.1. In Mathematica 10.2 I'm trying to integrate this piecewise continuous function, but ...
31 views

How to force a Range on Fit?

I have 1001 points between {x,-5, 5}. I wanted to fit a polynomial over the data but when i try: Fit[Flatten[data], {0, x, x^2, x^4, x^5, x^6}, x] ... the range ...
52 views

Internal DynamicModule steals scope of external DynamicModule

I have two dynamic objects, one nested in the other. Both have their own functions defined, as follows. I have simplified them to the point where they don't make much sense, but can still illustrate ...
331 views

How to obtain transparent animated gif via Export?

I have the following code to create animated GIFs: ...
205 views

Determine whether points lie within a cow

I would like to determine whether randomly-generated points ...
58 views

Why does Repeated not work in this case?

I think I don't understand how to use Repeated. I have a list for example list={a,b,a,b,a,b,a,a,b} I want to detect whether ...
108 views

Interesting “Tuples” application

I want to start with: {a,b},{c,d},{e,f} and end up with: {a,c,e},{a,c,f},{a,d,e},{a,d,f},{b,c,e},{b,c,f},{b,d,e},{b,d,f} ...
70 views

Fourier transform of Exp[x]/x

Could you please explain why Mathematica gives the following expression when taking Fourier transform of $\exp(\lambda z)/\lambda$? $$\frac{-\log(-z)+\log(z)}{\sqrt{2\pi}}$$ Why the answer does not ...
21 views

FindRoot outputs a lot of nlum and ReplaceAll errors before outputting (close) root

I'm trying to find the root of the root function when some other variable is subtracted. I.e. FindRoot[root[theta, r, h]-H, theta] Whenever I do this, FindRoot ...
31 views

check content of a Matrix

I have a matrix which contain rotated ellipses and points, how can I check if the element in the position {i,j} is either a point or an ellipse? the code is a bit longer but the structure is like: ...
30 views

Evaluating Root forms in a Table

When I put a Root form in table, the parameters of the Root form don't evaluate. I don't know how I can indexed values substituted into root form in the table to get have numeric output. ...
64 views

How to make a set of interdependent popup menus work?

Here is my code that is not working. ...
31 views

Arithmetic Progression [on hold]

How can I resolve these issues? I'm from Brazil and I don't have many things related to the subject here ** In an arithmetic progression of 6 Terms, the reason is 5. The product of the 1° with the ...
22 views

“Not enough memory” error even though plenty of memory still available

Summary: The evaluation of an Export[...] expression fails with a "Not enough memory available" error, but the value returned by ...
76 views

Multiple output cells, suppressed by semicolon

I'd like to write a function that outputs multiple cells, as in Multiple output cells, but not when the function is called with a semicolon at the end. Any idea how?
554 views

Row-Reduced-Echelon-Form with Equation Parameters for Consistent Systems

I often do row-reduced-echelon-form (RREF) calculations that involve parameters using the RowReduce command. Most times, I want to know which parameters make the system consistent. For example: ...
35 views

Fastest way for data input into StreamPlot function

I'm interested in looking at graphing the phase portraits of 2x2 autonomous ODEs, and I'm using the StreamPlot function. Here is one simple example: ...
72 views

How to convert Image3D object into Graphics3D object and vice versa?

There are some rendering options (for example, Lighting) which are associated with the Graphics3D objects. I cannot apply these ...
86 views

Finding negative sequences in a large list: optimization

I ran across an interesting challenge recently, and I was thinking this community would know how to optimize it. I have several data sets which have (currently) about 50k-100k points. The sets ...
60 views

Show and PlotLegend row spacing

In this toy example I make some plots, each with a legend, and combine them with Show. All the legends are assembled into a column which is helpful but it is too high for the size of plot. How can I ...
115 views

Why does the global variable exist here, where it was declared only in Module?

Why does the global variable a exist without having been created here? In ...
47 views

Dialog notebook with multiple popup menus

I'm trying to create a user interface in Mathematica; the user will enter specified information, it will be processed, and then data will be inserted into a MySQL database. The pieces work ...
111 views

Solving system of equations with (nested) Bessel Functions

I'm trying to find solutions to a system of equations which include Bessel functions. It feels like the problem for mathematica is that the arguments of the Bessel functions are functions themselves ...
95 views

How to convert arbitrary raw boxes directly into String?

This question is motivated by the recent question about searching inside of the NB files. According to the Documentation, ToString expects a high-level WL ...
25 views

Is there a syntax coloring type that highlights only when not in a list?

How do I define the syntax coloring of function myfunc so that it only colors the variable that is not in a list? For example, ...
52 views

Nonlinear Markov chain (numerical simulation)

Suppose you have a linear Markov process, and you can write it as x(t+1) = Ax(t). Here x is the vector of values, and A is the transition matrix. Since this is linear, it can be solved analytically, ...
35 views

Can “Part” be hold? [on hold]

I'm trying to define a function of which the length of the argument is undetermined. However, the exact form of this function depend on the length of the argument. And to save time, I have to evaluate ...
31 views

How to call a function with an arbitrary list as its arguments inside a functional? [duplicate]

I have the following functional defined (i.e. a function of another function) where variableList contains the variable (arguments if you wish) of the ...
20 views

What mathematica function to identify/approximate branching model\

I have a class of problems illustrated by the example below with emphasis on the fact that the sum of the variables is a constant. Is there a name for such problems? Which mathematica function would ...
33 views

Calculating the top left corner in a 2d field [on hold]

Given I have a field with several rectangles like shown in the picture. A point with its x and y coordinates are given. The height(h) and the width(w) are also given. How can I calculate the top ...
86 views

ListContourPlot cannot plot enormous datafile [on hold]

I would like to create a ListContourPlot from a list with about $7,000,000$ triplets (x,y,z) using the following code: ...
4 views

Isothermal coordinates [migrated]

Is there an application or interest in studying the isothermal surfaces where the metric is $ds^2=E∗(du^2+dv^2)$ and where $E>0$ is an harmonic function? I know that this metric is a special kind ...
39 views

Use If condition with ListPlot

Here is my code to use If condition with PLot: ...
37 views

Moving label with manipulate [duplicate]

In the following Manipulate, I would like to plot a distinct comment in each distinct zone which will move with the manipulation. Is it possible ? ...
169 views

OEIS A144311 Generating function

I'm looking for a way to use calculate OEIS A144311 efficiently in Mathematica. First, let's define the series. In one sense or another, this series considers the number between "relative" twin ...
40 views

How to arbitrarily label the points in ListPointPlot3D within Manipulate?

I want to label the points displayed in 3D within a Manipulate expression with arbitrary text. My code is as follows: ...
58 views

FunctionInterpolation produces many error messages when given high-precision input

Both FunctionInterpolation[1, {x, 0,1.00000000000000004}] and FunctionInterpolation[1.00000000000000004, {x, 0, 1}]; ...
430 views

Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this ...
8 views

ALS Matrix Convergence [migrated]

I came across this statement in some MapR documentation on ML in Spark: ALS is an iterative algorithm. During each iteration, the algorithm alternatively fixes one factor matrix and solves for ...
487 views

Toady,I have a problem about N,described as below: For example N[1/3, 5] (* ==> 0.33333*) and ...
47 views

Solving and Plotting Infinite sums over solutions to transcendental equation involving Bessel functions

I am trying to use Mathematica to plot the following equation $E(q,\Delta)$ vs $qa$, for set values of $D \Delta/a^2$ and $\bar\rho a/D$. I have looked at other stackexchange posts which deal with ...