All Questions

2
votes
0answers
151 views

Interfacing with a LabJack

I have a LabJack U3-HV and I wanted to use it with Mathematica to interface some hardware. I cannot find any information on the Internet; if I have to use Python, I will, but I would rather use ...
0
votes
1answer
70 views

Basic Row Traversal Question

Right now I'm using this For loop to do an operation to each row of a $n \times n$ matrix, I was trying to figure out how to do this with ...
-7
votes
4answers
445 views
7
votes
1answer
544 views

How to read data from IBM 32-bit floating point binary file ? (not the common IEEE !!!)

I am trying to read a binary file. This file records seismic data. Basically its first 3600 bytes are for the general file information, following are for seismic traces, each begins with 240 bytes for ...
0
votes
0answers
65 views

How can I replace very small scientific form of numbers in output with 0.0? [duplicate]

How cam I get rid of very small scientific form numbers in my output, replacing them with zero? (eg: 2.27682*10^-18 --> 0.0)
0
votes
1answer
84 views

Why does automatic scaling behave as it does in Plot? [duplicate]

The following command Plot[Exp[-(x^2)], {x, -5, 5}] draws while the following command Plot[Exp[-2 (x^2)], {x, -5, 5}] ...
0
votes
1answer
395 views

How does ListPlot3D interpolate data?

I have data of the form {{x1, y1, f(x1, y1}, {x2, y2, f(x2, y2)}, ...}. I need to interpolate the data to get an interpolated ...
2
votes
1answer
194 views

boundary problem

I have some conditions at t=0, like r1^2+r2^2=0.5 and x^2+y^2=6 and I want to find the right ...
2
votes
1answer
1k views

How can I draw an asymptotic bode plot?

When I use Mathematica to draw a bode plot, it always gives the precise version, like this: BodePlot[(10 (s + 3))/(s (s + 2) (s^2 + s + 2))] How can I draw the ...
0
votes
0answers
111 views

Cannot access the Database using the JDCB - ODBC

Runnig this code after building the ODBC connection for my access application named WPC : ...
3
votes
2answers
309 views

Find local maximum in 3D list

I have a set of data of the kind {{$x_i$, $y_i$, $z_i$}, ...} at randomly chosen points $x_i, y_i$. The $z_i$ are supposed to be a smooth function of the $x_i$ and $y_i$. Unfortunately they turn out ...
2
votes
1answer
105 views

Mean of Date variable data

I have hourly registered data as : ...
44
votes
3answers
1k views

When I can assume that all decimal digits returned by Mathematica are provably correct?

How to Control the Precision and Accuracy of Numerical Results Arbitrary-Precision Numbers Mathematica works with exact numbers and with two different types of approximate numbers: ...
4
votes
0answers
192 views

Strange behavior of undocumented RawArray and ArrayObject expressions

I discovered several strange results and inconsistencies while trying to understand what undocumented RawArray and ArrayObject ...
1
vote
1answer
108 views

Using Dot Product with InterpolatingFunctions

I am using NDSolve on a vector function $\mathbf y'(x)=f[\mathbf y(x)]$ with initial condition $\mathbf y_0$, where the dimension of the vector should be user-defined. ...
0
votes
2answers
640 views

How to generate a random data set with determined expected value and variance? [closed]

Recently I am doing my math homework and there is a question asking me to Come up with a dataset X that has at least 10 distinct numbers in it such that Expect[X] = 3.7, and Var[X] = 2.1. Actually I ...
3
votes
1answer
596 views

Normal and Tangent of Acceleration in 3D

I need to figure out how to find the Normal and Tangent of acceleration. I know the formula for the tangent of acceleration is $((Acceleration . Velocity)/(Velocity.Velocity))*Velocity$ and the normal ...
2
votes
2answers
411 views

How can I put an image on a surface [duplicate]

I want to paste an image on the surface of a 3D plot. For example consider this image which I want to paste on the surface of this sphere ...
5
votes
5answers
289 views

Excel column label from integer

I would like to create a function in Mathematica, which returns the equivalent Excel column label (e.g., A, Z, AA, AZ, and so on) given a column number. I think it can be done with ...
2
votes
1answer
176 views

Solving this system of equations produces an error message about badly conditioned matrix

I want to determine a balance distribution. Ü = {{0.4, 0.2, 0.3}, {0.3, 0.5, 0.2}, {0.3, 0.3, 0.5}}; and ...
10
votes
5answers
491 views

How to choose three points on the circle so that the triangle is not a right triangle?

I want to choose three points $A$, $B$, $C$ has integer coordinates on the circle $$(x+2)^2 + (y+1)^2 = 25$$ so that the triangle is not a right triangle. But I can not. I tried ...
0
votes
1answer
114 views

Finite precision - how to get rid of “near zeros” [duplicate]

I am performing a finite-precision operation on a matrix A which I know precisely; call the result B. The operation is taking ...
4
votes
1answer
205 views

My mistake or error in NDSolve?

I try to solve the following equation $$y'=y-2ye^{-0.8y}, \quad y(0)=0.7.$$ By some aruments I expect to have a positive solution $y(t)\geq0$, for all $t>0$, however, NDSolve shows that starting ...
1
vote
1answer
298 views

Measuring the area of non analytical regions in a plot [duplicate]

As the title says, I want to measure the area of different closed regions in a plot. Let me be more specific by giving a characteristic example. In the following figure, we observe that inside the ...
3
votes
0answers
226 views

Malliavin Derivative with Mathematica is it possible?

Is it possible to define a Malliavin calculus with Mathematica 9? Consider a random variables on the Wiener-space $\Omega=\mathcal{C}([0,1])$ of the form ...
0
votes
0answers
170 views

Integral of a transcendental equation

I have taken the following derivative of a transcendental equation using the D[...] function, as part of an approximation: ...
1
vote
1answer
187 views

Making an animated simulation without procedural loops

I'm still new to Mathematica and this is the first time I've wanted to do something more complicated than plotting and changing parameters of mathematical functions. I want to make a simple ...
4
votes
2answers
273 views

Numerical Integration with InverseErfc

I am trying to numerically integrate an equation that involves InverseErfc (embedded in the copula defined). The equation looks like the following: $$ \int_0^T \int_0^\infty \int_0^\infty ...
7
votes
3answers
378 views

I can't understand FindShortest Tour

I can't understand the function FindShortestTour because of the result: FindShortestTour[{ {0, 1}, {5, 1}, {2, 1}, {10, 1}}] ...
5
votes
2answers
2k views

How to find the Shortest Path, visiting ALL vertices, without coming back to the start (Hamiltonian Path, minimum distance)

A car has to pick up each person and take them to their destination. I am trying to find the shortest tour that will do this. How can I find the shortest path between any s and t.... visiting all ...
3
votes
2answers
105 views

More general pattern fails to match everything the more specific pattern does.

When I input this: MatchQ[x*SF[a,b] + y*SF[c,d], Plus[Times[x,SF[a,b]],Times[y,SF[c,d]]]] I get "True" as expected. But If I change it to: ...
3
votes
2answers
82 views

Manipulation of Automatic settings in a given case

Often I use the Automatic option to specify plot styles, plot ranges, image sizes, etc. I'd like to be able to apply some modifications to these automatically ...
4
votes
2answers
231 views

Drawing tool with Overlay

I combined two plots using Overlay. In the output plot I want to add few modifications. Usually I right click on the plot (for ...
2
votes
1answer
387 views

Trace of FullSimplify

I have a symbolic function and I used FullSimplify command to simplify the equation given below. I am calculating it by hand but I couldn't reach the same solution. ...
3
votes
1answer
120 views

Difference between Directory[] and NotebookDirectory[] .. a trailing /?

The following was the code: Directory[] NotebookDirectory[] The output was ...
3
votes
1answer
495 views

How to maximize a function over a rotation matrix?

I have list of pairs of points: $\{(x_i,y_i)\}_{1\le i\le n}$, $x_i \in \mathbb{R}^3$, $y_i \in\mathbb{R}^2$ and would like to optimize over a rotation $R \in SO(3)$, a translation $t \in ...
1
vote
1answer
184 views

Calling several compiled functions inside another

Below, there is an example how I tried to call the compiled function "position" (which i got from this link position) inside another one. ...
6
votes
1answer
806 views

Simplify $\cos(n \pi)$ and $\sin(n \pi)$ when n is an integer

I was trying to calculate this integral in Mathematica 9: 2/π Integrate[ Cosh[a x] Cos[n x], {x, 0, π}, Assumptions -> n ∈ Integers] I got as a result : ...
8
votes
1answer
204 views

Have the Random functions changed?

I re-ran a program I wrote for Mathematica v8, now on v9, and it appears to generate different RandomInteger numbers, even though I use the same ...
2
votes
1answer
570 views

How to import a Microsoft Word document into Mathematica?

I have a Microsoft Word document in DOCX format. I need to import it into Mathematica as a String preserving all formatting (font, size, bold/italic style, colors, ...
2
votes
0answers
123 views

Errors importing UTF8 file to mathematica

I'm trying to import this file: Import["https://dl.dropboxusercontent.com/u/35192406/jarlaxxe_tweets.\ csv", CharacterEncoding -> "UTF8"] But I am getting ...
0
votes
1answer
252 views

Reverse after ImageData? [duplicate]

Why should we do a Reverse on the image data after an ImageTake ? For example: ...
8
votes
3answers
275 views

Have I found a big difference between using the short form and the long form of a pure function?

By referring to the Mathematica documentation, I learned to use ##2 to represent all the arguments but the first one. This is a brief way to represent a pattern ...
1
vote
0answers
268 views

Change of coordinates for an InterpolatingFunction

This is a toy example of the question I have but I think it illustrates the point. I have a function y[x] which is an interpolating function. Let's define it ...
0
votes
1answer
115 views

Remove controls in Animate with exception of PlayPauseButton

I'd like to retain the PlayPauseButton in the Animate and remove all other Controls ...
2
votes
1answer
561 views

How to take the derivative w.r.t. an arbitrary function?

EDIT: The answer posted by @Jens works for built-in functions only. However I'm starting to wonder if this is related to my Mathematica install somehow. I have version 7. Here is an example in the ...
4
votes
2answers
228 views

Modified Cell Different Display

Is there a way to show maybe a slightly different color, or change the cell bracketing color of a Mathematica cell when it has been modified? Ideally it would be nice to follow the standard of ...
1
vote
1answer
118 views

Appropriate application of plotstyle directives

I am attempting to style a Plot in which all of the lines are Thick and I have selected the colors manually: ...
0
votes
1answer
272 views

BarChart with ScalingFunctions -> “Log”, Fixed axis

I want to make an animated BarChart. In this I want to plot different tables which range from $10^{-60}$ to $1$. For example: ...
3
votes
3answers
684 views

How to integrate a function over a 3D planar polygon?

I am trying to integrate a function over a planar polygon in 3D. In 2D, this is fairly straightforward, using either answer from this question (I use the second answer). If we use an equilateral ...

15 30 50 per page