0
votes
1answer
129 views

How to simulate a multivariate recursive system from a list

New to mathematica, trying to use Eric Swanson's Pertubation AIM program to solve DSGE models. His code produces a solution as a list or a table. My question is how do I use this list to simulate the ...
3
votes
1answer
242 views

Utterly confounding behaviour in Mathematica 9 DSolve

I've been baffled by a lot of the behaviours of Mathematica 9 — so much that I regret upgrading my copy of Mathematica 8 (I would downgrade but I'm currently on vacation). Here is an example: ...
1
vote
1answer
116 views

Incorporating a Manipulation in an Animation

I am having trouble incorporating a manipulation into my animation. I want to be able to maniuplate the 5 constants at the beginning. Am I going to need to combine all of the code into one string? ...
7
votes
1answer
229 views

How to scale edge length and keep layout of edge-weighted Graph?

I love using Graph as structure to store and visualize my data in Mathematica. Consider the following simple example for creating a ...
1
vote
1answer
173 views

Style markers in strings

I'm dealing with strings in Mathematica and I would love to handle their stylling in the most cenvenient way. Without loss of generality, let's assume I want to make some parts of string ...
3
votes
5answers
914 views

Find the slope between adjacent points in a list

I have a list of two dimensional points that are ordered by their x-coordinate. I would like to calculate the slope between all adjacent points. I'm familiar with the use of pure functions in Sort ...
1
vote
1answer
192 views

Using new symbol in WhenEvent in NDSolve

This is an example in Mathematica's help document. ...
15
votes
3answers
950 views

List of dangerous functions

I no longer believe it is a good idea to work with a list of dangerous functions. I have tried to edit the question is such a way that it respects my earlier perspective, but also so that it does not ...
1
vote
1answer
600 views

The underlying process of Integrate[] [duplicate]

Integrate[x^4 E^-x^2, {x, 0, +∞}] Output: (3 Sqrt[π])/8 Can someone explain to me the specific calculation process ?
8
votes
1answer
1k views

Linear programming with many variables and parameters

I am trying to reconstruct the answer that is given in this report. (page 153 in Appendix B; Section B.2.1). They are given variables, parameters, constraints, and the objective function to minimize. ...
1
vote
1answer
140 views

Using Select on list of vectors [duplicate]

I have a dataset, where each element in the list is a vector as in data = Table[{i, 2 i, 3 i}, {i, 1, 10}] As an example, I am interested in the entries where ...
5
votes
0answers
339 views

Mathematica inserts extra \left and \right for absolute values in LaTeX output

Type the following in a Mathematica DisplayFormula cell(other styles may also encounter this problem): Esc+l+|+Esc and Esc+r+|+Esc, and save as LaTeX. Note: See the difference of the character ...
9
votes
2answers
333 views

Symbolic integration fails while numerical integration succeeds

I am hoping to evaluate the following integral Integrate[((r^3 - 7)^(2/3)*(1 - (r^3 - 7)^(2/3)/r^2))/r^3, {r, 2, Infinity}] but Mathematica informs me that this ...
1
vote
2answers
1k views

Simplifying expressions with square roots

I would like Mathematica to simplify this expression: $4 \left(16 \sqrt{\left(-1+2 c^2\right)^2}-32 c^2 \sqrt{\left(-1+2 c^2\right)^2}+\sqrt{\left(1-8 c^2+8 c^4\right)^2}\right)^2$ ...
1
vote
1answer
55 views

Export and Import with graphics characters

I exported a list of characters say: Export["hello.txt", {t, r, $\theta$, $\phi$}, "List"]; the file has the correct symbols when opened with a text editor, however, when I imported it with ...
1
vote
2answers
109 views

Evaluation of elements in a list and then sorting them

This is probably a simple problem, but I'm having a lot of issues with it because I'm unfamiliar with Mathematica syntax. I have a list ...
8
votes
1answer
169 views

The Flat Attribute, Unevaluated and the Evaluation Process

To make this question easy to follow let's give some symbols a couple attributes. Attributes[f] = {Flat}; Attributes[s] = {Orderless}; Now consider the ...
2
votes
1answer
187 views

Autoupdate Dynamic Variable and Selectable

Does there exist a technique to construct a Cell that allows you to both auto update a Dynamic variable and allows you select the code while the variable is being ...
7
votes
1answer
425 views

Removing the edge features of an image while enhancing internal connectors

I picked up the following leaf today while going for a walk. And wanted then to run the same analysis that @Vitaly Kaurov did for rivers under this posting Measuring Fractal Dimensions of natural ...
9
votes
2answers
231 views

Partitioning a superset of coordinates into subsets that generate continuous curves

Consider the data set corresponding to recorded trajectories for a particle: ...
8
votes
3answers
496 views

How can I calculate the perimeter of an equation-defined curve?

This is how the curve looks like: ...
1
vote
3answers
137 views
1
vote
1answer
268 views

Color inversion using ArrayPlot

I have a 3D data that I want to visualise its each slice with ArrayPlot. However, there is a problem the way it represents the data. As, ArrayPlot by default generates grayscale output, in which ...
4
votes
2answers
387 views

How to make a conditioning plot?

I'd like to make a conditioning plot just like coplot in R. Is there a pre-made solution or do I have to make a bunch of plots individually? Edit: This is an example from r screenshots. It is a way ...
3
votes
1answer
398 views

Exception/Error handling using returns codes

There is good explanation available for error handling on this and similar links. Here there is information on handling inappropriate input arguments and handling unprocessed functions using ...
3
votes
1answer
451 views

Generating a “best fit” curve to a set of noisy data corresponding to a moving object

Please note that this is an extension of a previous question: Interpolating a sparse list of two-dimensional coordinates We have an ordered array of coordinates corresponding to the position of an ...
3
votes
2answers
179 views

Interpolating a sparse list of two-dimensional coordinates

I've run into a problem where I have an ordered array of sets of coordinates, for example: ...
3
votes
3answers
223 views

Is there a fast method of generating a Standard Deviation image from a frame stack?

Imagine I have a stack of image frames, $(f_1, ..., f_N) \in F$, where each $f_i$ has the same set of $(x,y)$ dimensions. Using these frames, I'd like to create an image where each pixel in the image ...
6
votes
2answers
176 views

Series resulting in “No more memory available.”

Is there any way to force Mathematica to come up with the closed form to Sum[1/(i^18 (i^2 + j^2)), {i, 1, Infinity}, {j, 1, Infinity}] or ...
1
vote
1answer
380 views

Problem with Fourier and InverseFourier function

I have the following code Image[img, ImageSize -> 300] data = ImageData[img]; fdct = Fourier[data] tdata = InverseFourier[fdct]; Image[tdata] but it seems to ...
14
votes
1answer
405 views

What is the real default CellEvaluationFunction?

The default CellEvaluationFunction is Identity but one can quickly see that this is handled specially as an equivalent function, ...
4
votes
2answers
213 views

How to fold output cells by default?

In Mathematica the default behavior of output cells is to pop up after the kernel has processed the input cells and got a result. I know I could add ; in the end of ...
1
vote
3answers
212 views

Defining a polygon by clicking on an image [duplicate]

Imagine I have some image, $I$, and I'd like to define a polygon by sequentially clicking on the image to define vertices $(v_1, ...) \in V$, where vertices $v_i$ and $v_j$ share an edge if $j = ...
10
votes
1answer
149 views

Functions returns Command Completion Output

Is there a function that returns the output as if you invoked Command Completion. To help clarify I am looking for a function that returns the Cell Data as if you invoked ...
1
vote
0answers
31 views

Symbol created in unevaluated second argument of If [duplicate]

Apologies for the long question title, but I couldn't come up with something shorter to describe the following. Starting with a clean session, there are no symbols in, let's say, ...
3
votes
3answers
318 views

Temporarily redirect the output of Print[ ] to a second file

I have started using Mathematica to automate file backup operations. The logistics I need make Mathematica a good choice. I am testing and developing the Notebook manually, and ...
2
votes
1answer
125 views

Can I apply a ColorFunction to FaceGrids, or otherwise have FaceGrids with varying color?

I want to make a 3d plot with FaceGrids with a certain color scheme. Specifically, I'd like them to be one color below a diagonal line, and a different color above ...
1
vote
1answer
305 views

Initialization Cells in CDF

I am wanting to run about 15 pages of initialization cells in a CDF, but can't seem to do so. I have set the InitializationCellEvaluation to True and InitializationCellWarning to False, but it doesn't ...
2
votes
0answers
53 views

How to ensure that command line variables are secure for MathKernel scripts?

Suppose I write a Mathematica script, called test.m, like the following: Print["Hello, World!"]; test = ToExpression[$CommandLine[[-1]]]; Print["I'm alive!"]; ...
1
vote
2answers
221 views

URLFetch functionality for a Persian website

I want to fetch the content of a Persian website. I tried URLFetch["http://www.tsetmc.com/"] Why is Mathematica unable to recode the characters in the results ...
0
votes
1answer
598 views

PDF of binomial distribution and mixed binomial distribution

I want to plot the PDF of binomial distributed function and a mixed binomial distributed function, therefore I entered for the binomial distribution function the following: ...
8
votes
1answer
537 views

Problems with “Test Connectivity” and the Pacletserver

I know there has been a similar questions to this already but the solution did not work for me so here again: I have internet connection and I can execute such commands like: ...
1
vote
2answers
390 views

Placing a zero at coordinate center when plotting with Ticks -> None

I'd like to plot a certain function where only its qualitative progession shall be emphasized. Thus, using the Ticks->None option seems to be appropriate. ...
1
vote
1answer
74 views

How can I get a horizontally centered input window?

This example displays a input window at a position of 675 from the left. ...
10
votes
4answers
236 views

Is it possible to separately call the default value of a variable which isn't at the end of the sequence?

After reading this post I recalled an old question I once met. We know that we can set default values for variables of a function: ...
21
votes
2answers
722 views

Is there any way to define pure functions with optional arguments?

For example consider the following function: Function[{u,v},u^2+v^4] Is there anyway to define default values for the variables ...
-3
votes
1answer
3k views

Determine the 2D-Fourier transform of an Image

I am new to Mathematica and using Version 8.0. I want to calculate the 2D-Fourier Transform of a digital image and see its Magnitude and Phase Spectrum, and reconstruct it.
3
votes
2answers
167 views

Compile error from If but not from Piecewise

Consider this: point={1.,2.}; f1 = Compile[{{t, _Real}}, Evaluate[Block[{a, b}, {a, b} = point; If[t > 0., a*b*Sin[t], 0.]]]]; f1[2.] ...
1
vote
1answer
177 views

How can I eliminate $x_1$ from my two ODEs?

How can I get Mathematica to eliminate $x_1$ in the equations in the first box to achieve the equation in the second box? My code: ...
2
votes
1answer
870 views

DSolve doesn't find a solution

I have this partial differential equation (G and M are constants): and a solution is: Mathematica doesn't find any solutions. My code for DSolve is: ...

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