All Questions

1
vote
1answer
261 views

Difficulty with computing a limit

I meet some difficulties when trying to compute this limit, ...
0
votes
0answers
61 views

Connect to a MS Access database (*.accdb) [duplicate]

The JDBC Connections section of the help file http://reference.wolfram.com/mathematica/DatabaseLink/tutorial/DatabaseConnections.html gives me the impression that I can connect to a MS Access Database ...
17
votes
4answers
815 views

Generating an “average curve” from a dense set of “semicontinuous curves” which clear trends

This question is related to a previous one of mine: Partitioning a superset of coordinates into subsets that generate continuous curves, where the challenge was to partition a data set into two ...
2
votes
1answer
117 views

NotebookWrite undo

Is there way to make NotebookWrites undooable? For example let's say I open a new notebook and then run. ...
5
votes
3answers
310 views

Unexpected Setter Bar Behavior when Manipulate Nested in Dynamic Module

Consider this code: DynamicModule[{x, y}, x[t_] := t^2 + 5; y[t_] := t^3 + 5; Manipulate[Plot[fcn[t], {t, -5, 5}], {fcn, {x -> "Square", y -> "Cubic"}}]] ...
1
vote
1answer
231 views

Finding the time at which an Ito process satisfies a constraint

I want to run an Ito stochastic process. I have the following parameters ...
4
votes
1answer
454 views

How to create an interactive map of the 50 states showing certain data in tool tips boxes for health care policy development?

To create a means of displaying information about the distribution of primary care providers, the population density and the average yearly Medicare expenditure per enrollee for each state, I would ...
0
votes
2answers
414 views

Manipulating differential equations

I would be very grateful if anyone could help with manipulating the solution to the system of differential equations below. I've tried just about everything I can think of all to no avail. The code ...
4
votes
1answer
625 views

Plotting a 2D shape along a 3D parametric function curve

Say I have a 3D curve that is parametrically defined. How would I be able to plot shapes like figure 8s whose centers are aligned along the 3D curve? Say the curve was: ...
4
votes
1answer
130 views

Overlaying location pointer on to a png file

So I have started off with importing a png image of size $512\times 1024$ px. I have then created two locators as demonstrated on the Wolfram tutorials: ...
2
votes
1answer
89 views

Replace inverse function

I'm solving an expression like so: Solve[u[x] == u[a] + u[b], x] Mathematica returns {{x->(u^(-1))[u[a]+u[b]]}} If I ...
2
votes
0answers
163 views

Using WhenEvent for derivative of discontinuous function

I have a discontinuous function ($u(t)$, a square wave) and I would like WhenEvent to trigger when the signal goes high/low, i.e. when the value of $u(t)$ changes. ...
1
vote
0answers
68 views

Is it possible for Mathematica to give the step by step process of Reduce command? [duplicate]

Input: Reduce[3 x^2 - 2 a x + a^2 - 1 >= 0 && x > a, x] // TraditionalForm Output: ...
1
vote
3answers
388 views

RowReduce for symbolic matrices

I'd like to invoke RowReduce on some matrices with a time parameter. For example consider A = {{1, 0}, {0, t}} If ...
7
votes
6answers
337 views

Assigning row of values to a lower triangular matrix

I want to assign a linear row of values to the elements of a lower triangular matrix, i.e., if the row of values is {1,2,3,4}, then the matrix (4 X 4) should be: ...
0
votes
3answers
113 views

Formatting the output of ComponentMeasurements

I have some code written here which uses ComponentMeasurements to output some data, specifically the one below: ...
6
votes
4answers
263 views

PlotLabel moves, when i rotate my 3D graphic

How can I stop the label from moving up and down, when rotating using the mouse? ...
7
votes
3answers
144 views

How can I set default size for some characters

Alt++ could adjust the size, but how to store the satisfactory size? For example: Each time I type |, its size is (I assume) 12. How to make its effect like adding ...
4
votes
3answers
481 views

Connect to remote Ms-sql Database

I can connect to the local Database(installed in my system) from Mathematica via ...
10
votes
5answers
381 views

ListPlot under conditions

I have a data file containing several columns and thousands lines of data. Below I present a small portion of it, in order to express my issue: ...
1
vote
1answer
137 views

ImageLines Segmented options

I have tried utilising the ImageLines function, and its accompanying Segmented setting. However, the segmentation doesn't appear to allow for its variables to be fine tuned, at least not according to ...
7
votes
1answer
194 views

Error while exporting to Excel with named sheets

Using Mathematica v9.0.1 This example is from the docs: ...
10
votes
2answers
290 views

how to make cursor jump automatically to next input cell after evaluating previous one?

When making separate cells in order to make separate computations to better see the result of each one before going to the next cell to do the next computation (which is a good way of doing things), ...
13
votes
1answer
258 views

Randomness test suites that can be invoked from Mathematica

There are several test suites referenced at csrc.nist.gov designed to test a (pseudo-)random byte sequence for randomness, and discover possible skews, correlations, patterns, or other hidden ...
3
votes
1answer
153 views

Exporting large png results in completely black image

When trying to export an Image as PNG the resulting file is a completely black image. This happens only for certain images I have not been able to determine exactly ...
2
votes
2answers
359 views

How can I remove text headers when importing a numeric table

I have a file let's say 1.txt having numbers like: fgdgfdg fhdfdh 0.000105533 1.00E-04 0.222281 1.00E-04 0.444456 1.00E-04 0.666631 1.00E-04 asdas ddfdsfsd 0.111193 0.166733 ...
1
vote
2answers
347 views

Finding shortest non-zero vector $x$ satisfying $Ax=0 \pmod q$

Let $n$, $m$, and $q$ be positive integers (with $m > n$), and $A$ be a matrix over $\mathbb{Z}_q^{n \times m}$. Using Mathematica, I want to find the shortest non-zero vectors $x \in ...
0
votes
1answer
121 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
235 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
114 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
212 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
153 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
818 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
183 views

Using new symbol in WhenEvent in NDSolve

This is an example in Mathematica's help document. ...
15
votes
3answers
923 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
449 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 ?
7
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
133 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
305 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
323 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
875 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
53 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
106 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 ...
7
votes
1answer
160 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
179 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
391 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
221 views

Partitioning a superset of coordinates into subsets that generate continuous curves

Consider the data set corresponding to recorded trajectories for a particle: ...
5
votes
1answer
339 views

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

This is how the curve looks like: ...
1
vote
3answers
135 views
1
vote
1answer
218 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 ...

15 30 50 per page