# All Questions

482 views

### How could I get the value of y[t] at each specific interpolation point?

sol = NDSolve[{Derivative[2][y][t] + Sin[y[t]] == 0, Derivative[1][y][0] == 0, y[0] == 1}, y, {t, 0, 2}] the above-mentioned differential equations can be solved ...
201 views

### Is it possible to replicate the “magic” of OptionPatterns[] with DynamicModule's local variables?

Creating richer interactive interfaces that are generated by a DynamicModule invariably requires more complex data structures and in particular, a larger argument ...
335 views

### How to output from a .NET console app to an existing Notebook in Mathematica?

I'm wondering if its possible push output from a .NET console application to an existing Notebook that is open in Mathematica. The reason I'd like this is that I want to use Mathematica as a ...
390 views

### How to perform DialogInput operation within Button

Can someone clarify how to perform a DialogInput operation within a Button? I wrote some code for that but it's not working. ...
5k views

### Importing from Excel

I'm trying to import a matrix from Excel to Mathematica. My code is: Import["desktop/stproj.xls", "xls", data, 1] The output is some weird stuff about population ...
1k views

### Trying to simplify Root expressions from the output of Eigenvalues

I am trying to calculate eigenvalues of a sparse matrix with only two distinct non-zero elements, here Alpha and Beta, which are both negative reals. Mathematica returns some complex expressions with ...
241 views

### How to work around Column cutting off a pixel row from images?

I have a problem where Column will occasionally cut off a single pixel from the top of images. To reproduce the problem, evaluate this: ...
115 views

### Customizing a graph (Dashing, PlotMarkers, Labeled)

There are actually several questions here but I thought they are closely related so I should not split into several posts. Here we go... I have the following list ...
117 views

### How does Mathematica calculate its AdjacencyMatrix[ ] and VertexDegree[ ]

I define a graph: ...
124 views

### Reordering numerically calculated eigenvalues assuming smooth dependence on a parameter

As was discussed in a different question here on SE (link) if you compute eigenvalues numerically of a matrix which depends on a parameter y, the resulting plot of ...
680 views

### How to draw confidence ellipse from a covariance matrix?

I am studying a two-dimensional dataset, whose mean vector and covariance matrix are the following: ...
111 views

### Reflecting lines in ellipses: speed up the code?

I have the following code which calculates a list of points that a line would take after bouncing off various ellipses. ...
171 views

### Convert C program using mathlink to WSTP

I have been using heavily a custom frontend to mathematica based on mathlink. I derived it from http://library.wolfram.com/infocenter/Demos/174/frontend.c?file_id=4692 . I just learned that mathlink ...
189 views

### Beginner CUDA: two dimensional blocks and two dimensional threads?

This is a follow up question to: CUDA: setting grid dimensions. The purpose of the question is to understand how Mathematica is interfacing with CUDA's architecture. I have a related question/request ...
394 views

### List Contour Plot: Delete some contour lines, but keep the colors

I'm trying to make a Contour plot of a set of data of the kind: $(x,y,f(x,y))$ What i'd like to do is to remove the majority of the iso-line and just leave two of them, but keeping the changing of ...
517 views

### Sum over multiple indices

I would like to be able to enter the following left hand side of an identity. I can write the right hand side (i think) but am not sure about the left. The Left hand side is ...
289 views

### Test Goodness of fit for FindFit

Is there any way to get an estimate of the goodness of fit from FindFit, for instance getting the final error? The documentation doesn't provide any hints, and a quick Google search didn't return any ...
113 views

### BarChart rasterized in EMF export

My boss wants several Mathematica graphics as vector graphics in EMF format. All my plots are exported neatly, except for a BarChart which gets rasterized for no apparent reason: ...
100 views

### Saving data from NonlinearModelFit

If you use NonlinearModelFit the results are put into some sort of output package. How do you save these packages so that you can go back to them later? My particular problem is that I generating ...
284 views

### Expectation of a family of random variables

I did some search here, but seems that no one asked about this. I want to define a family of independent and identically distributed random variables, $x_1,...,x_n$, and then calculates the expected ...
171 views

### Determining the dimension of a probability distribution

Functions like Mean and RandomVariate clearly infer the dimension of the distribution passed to them. One can also usually ...
233 views

### Fixed-Point Numbers in Mathematica

I am working with a library that needs input in a Fixed Point notation. I’d like to figure out a way to convert the floating point results into fixed point representation. The fixed point length is ...
281 views

### Selecting for 2D points that are within a threshold distance of an upper- and lower-bound number of points

I have a very large set of 2D points: numberOf2DPoints = 10^6; pointList = RandomReal[{0, 1000}, {numberOf2DPoints, 2}]; I'd like to find a way to quickly ...
268 views

### How to partition a list into sublists in a similar way to Histogram

I have a list of list as below (I show part of it) ...
221 views

### Separating disconnected graph objects without losing vertex coordinate assignments

Say I have a graph Gtest, which has multiple disconnected components. I found that I can isolate individual components while retaining vertex coordinate ...
362 views

### Simplifying expressions involving Sum

I am trying to use Mathematica to simplify a symbolic expression involving Sum. Particularly, I define a sum via ...
551 views

### Need help with exception handling

I have read the docs for Catch, Throw, and friends multiple times, and I confess that I find them utterly incomprehensible... ...
299 views

### Conjugating symbolic expression

I am trying to conjugate a symbolic expression, and I have explicitly stated the real terms. However, I simply can't get it to work: ...
247 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 ...
185 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 ...
1k views

### Forecast Future Stock Prices - Brownian Motion - Again

excuse me, I think I have here a technical problem with Mathematica yesterday I posted the question with the title: Forecast Future Stock Prices - Brownian Motion I am still not very experienced but ...
101 views

### Some _atomic elements' TreeForm looks confusing with Level in appearance

In[1]:= Level[1/2,{-1}] Out[1]= {1/2} TreeForm[1/2] ...
266 views

### What causes strange line artifacts to appear in plots with certain PlotRanges?

I have seen this strange plotting artifact occur before and I was able to make it go away by changing the PlotRange. However, this time I need the prescribed PlotRange to be what I define and I get a ...
1k views

### ODE and BVP: NDSolve errors

The mathematical problem is shown here. I tried to solve writing the ...
380 views

### Use different kernels for different Notebooks

I know that the command LaunchKernels[] starts up four kernels on my machine: ...
2k views

### How to increase the number of minor ticks in a plot?

I want to increase the number of minor ticks in a plot, but I don't want to label them. I searched through this site and also Mathematica documentation, but I didn't find any solution yet. Could ...
246 views

### Autocomplete short symbol names in non-global context

Is it possible in v9 to autocomplete the short symbol names when one is operating in a context other than Global`? I.e. after evaluating the following: ...
2k views

### NDSolve does not respond

For some sets of constants, NDSolve gives me true solutions, but when I try for example, T = 1/(2*2200), Mathematica does not respond. What can I do? The code below ...
198 views

### Dynamic application of several polynomials

I know how to get the 'resulting image' (y) from the application of a certain function (f) (here represented as the coefficients of a polynomial) over a certain interval (x): ...
547 views

### How to get the determinant and inverse of a large sparse symmetric matrix?

For example, the following is a $12\times 12$ symmetric matrix. Det and Inverse take too much time and don't even work on my ...
929 views

### Solve with v9 (issues with Subscript, Overscript, Superscript etc)

The way Solve works has changed in v9 ... in essence, to get the answers that one obtained under v8, one now often has to specify a lot more information about all ...
2k views

### Adding contour lines to a 3D plot?

I am having trouble getting contour lines on a 3D plot (ListPlot3D). I have tried ListContourPlot3D, but that gives me a really weird looking graph with a ton of dfferent levels. What I would like is ...
370 views

### How to change alignment of Grid/Matrix created using menu (Insert->Matrix/Table->New)

When I create a Grid using the menu, as follows: and then start to add data, I'd like to make the alignment to be left and not center which is the default ...
1k views

### Obtaining the Fourier transform of an operator

We know that if we have a function $f(x)$, and we call $g(\omega)$ its Fourier transform, then the Fourier transform of $x f(x)$ is $$\imath \frac{\mathrm{d} g(\omega))}{\mathrm{d}\omega}$$ and ...
3k views

### Plot Even Piecewise function

Is it possible in Mathematica to plot an even piecewise function like: $f(x) = \begin{cases} 3t , 0 \le t \le \frac{\pi}{2} \\ 3t + 6 , \frac{\pi}{2} \le t \le \pi \end{cases}$ which has ...
242 views

### Customizing FrameTicks in DistributionChart

So I have been fighting with this for a while. I'm trying to get custom frame ticks on both the left and right side of a DistributionChart. It's not going very ...
697 views