# All Questions

536 views

### How do I find the amount of free space on disk?

I know a workaround, where one calculates sizes of all files and then you subtract this from your default space, but is there any direct way to do it? Simplicity and speed are important. There's the ...
190 views

### LogPlot does not show all points

LogPlot ignores points which are going to "too high" values: ...
2k views

### Is it possible to generate a Hasse Diagram for a defined relation?

I'm looking for a way to create a Hasse Diagram from a given partial order binary relation. The relation will be given explicitly, for example: ...
2k views

I want to create a two-dimensional plot using data from an external file. This file contains several triplets of numbers. The first two columns indicate the x and y position, while the third one works ...
4k views

### Mathematica function intersection points with 3D grid

I need to produce a 3-dimensional equispaced grid over a given function in a way, that I can calculate intersection points of the function with the grids edges. So my first question is how to produce ...
534 views

### Finding connected components in an array

I have an $w\times h$ array with non-negative integers. I wish to partition the set of coordinates $(c,r)$ with $1\leq c \leq w$ and $1\leq r \leq h$, in subsets, so that each subset corresponds to a ...
2k views

### Export Table from Mathematica into specific cells Excel

How can I export a table to Excel - to specific cells, e.g. D1-E2? Background: I want to compare results, and it's easier to have the results on one spreadsheet. I'm using Mathematica 6. This is my ...
567 views

### How to overload SystemStringJoin to automatically use ToString on arguments?

I am using an overloaded version of the StringJoin function since years now, without any problem, as I've invested a lot of time and effort earlier to make its ...
164 views

### How does thing[“property”] syntax work?

Many builtin "things" support the (usually undocumented) syntax thing["property"], and usually the available properties can be listed using thing["Properties"] (thing["Methods"] might work too). ...
440 views

### Representative Smooth Kernel Distribution from Truncated Distribution

I am trying to produce a better distribution from a dataset that is bounded to be greater than 0. Here is an example distribution from the documentation that mimics the behavior of the actual dataset: ...
334 views

### Cannot Get Numerical Results to Match

I try this numerical summation (in two parts) ...
228 views

### Keeping vertexcoordinates after adding a new vertex

I want to add a new vertex to a graph, with fixed VertexCoordinates but when I use VertexAdd, the new graph does not have the VertexCoordinates of the previous one. ...
1k views

### Select a repeated element in a list

I want to select all elements that repeat 4 times in the list. I propose this code ...
251 views

### How to understand the process of ListCorrelate when it in two-dimensional condition?

Toady,I learn a function ListCorrelate,and I can understand process of execution his result in one-dimensional. However,the ...
2k views

### Any way to prevent Mac firewall from asking to allow connections all the time?

Whenever I start Mathematica 8 on my Mac the built-in Mac OS firewall asks if I want to allow JLink to accept incoming connections. Then, during running, I'll get the same question about Mathematica....
730 views

### Fitting data to an ARProcess using FindProcessParameters

I have 50 data points that I would like to represent as an AR(4) process. I'd like to over-plot the behaivor of the estimated process model with that of the original (raw) data before I use the model ...
549 views

### Parallel optimization of Markov Chain Monte Carlo

I'm trying to reduce the computation time of a MCMC simulation. Essentially I have a set of particles performing a random walk in a periodic random potential. The particles are independent and every ...
94 views

### Problem Using Evaluated Replace with Associations

If I define some function like: toISOdate[data_List]:=DateString[data,{"Year","-","Month","-","Day"}] and try to applicate it in an ...
240 views

### How should I deal with messages being produced by my Manipulate?

I have made a knockoff of John Polking's dfield for a web-embedded CDF (via Enterprise Mathematica). My code extends that from Belisarius who last year showed me how to use ...
270 views

### Implement functions that depend on previous value in NDSolve

I want to numerically solve a system of differential equations in Mathematica, say for example $\frac{dx}{dt} = f(x,y,t) \\ \frac{dy}{dt} = g(x,y,t)$ for $x(t), y(t)$. However, the functions depend ...
459 views

### ListPlot3D of a set of points in a non-convex region

I would like to plot a set of points in the same style as ListPlot3D does, but only in a non-convex region that I can specify (e.g. using a ...
559 views

### Why is there a huge performance gap using Map with more than 100 List entries

im using Map on a List like this: cube= {{1, 1, 1}, {1, 1, 2}, {1, 1, 3}, {1, 1, 4}, ... , {5, 5, 4}, {5, 5, 5}} Mapping the whole List with 125 entries takes ...
141 views

### Inaccurate Heliocentric coordinates of PlanetaryMoonData

I have noticed that the heliocentric coordinates obtained with PlanetaryMoonData are very inaccurate. Fore example, consider the Galilean moons of Jupiter: ...
600 views

### How to extract RGB arguments as a list

Although the following lines of code work fine they are very awkward. My questions are below a = RGBColor[1, 0, 0] b = RGBColor[0, 1, 0] Is there a more compact ...
363 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 ...
808 views

### Is there anything like a C pointer (or returning a reference) in $Mathematica$?

I want to do in Mathematica what the following does in C. ...
422 views

### Exporting a rasterized Row of Graphics

I'm running some code based on @R.M.'s answer to this question to create a couple plots side by side. I want to export the plots rasterized to a png. However, when I ...
316 views

### HoldForm does not Hold Form for fractions sometimes

I'm facing a strange behavior of HoldForm. I need to display 1/2*3/4 in LaTeX like this : $$\frac{1}{2} \times \frac{3}{4}$$ ...
176 views

### Ordered associations

Mathematica 10 has introduced Associations, elsewhere known as hash tables or dictionaries. Is there Ordered equivalent like in Python, Java, .NET? The data structure should remember the order in ...
355 views

### Histogram of a very large dataset?

I have a very large dataset stored in a file (over 2GB). The file contains a tab-separated table of floating-point numbers. I want to do an Histogram of all the numbers in the table. But if I try to ...
9k views

### How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

I'm trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example, ...
365 views

### Getting all physical units with prefixes

How we can get the list with all physical units and prefixes from WolframAlpha and make symbols from the result to be equal their corresponding quantities like described in this post?
1k views

### What is the default ColorFunction for 3D plots?

This should be a really simple question, but it isn't in the documentation for some perverse reason. I like the default ColorFunction that Mathematica uses for <...
735 views

### Labelling objects in a picture with numbers

I need help processing a biology bacteria picture. I just started learning Mathematica and I hope you guys can use a simple method to help me solve the problem, please do not use super complicated ...
97 views

I am using Mathematica 9 on Windows 8, and I regularly want to use cell styles such as Section, SubSection and so on. If I click the + button before creating a new ...
153 views

### Multidimensional arbitrary precision spline interpolation on the grid

This question is a generalization of the previous one for multiple dimensions. In the answer to that question an implementation for the clamped spline interpolation for 1D case and arbitrary degree of ...
660 views

I've upgraded to Mathematica 9.0 on Ubuntu 12.04 with the latest Nvidia driver (304.64). I load CUDA by using, as usual, Needs["CUDALink"]. ...
743 views

### Triangle mapped on a sphere in $\mathbb R^3$?

How can I map a triangle on a sphere? I want to visualize (plot or animate) it for my student in Non-Euclidean geometry. I have no restrictions on the triangle's kind or on the sphere in $\mathbb R^3$....
673 views

### Is Table the only functional way to construct nested loops in Mathematica?

Suppose you have a cubic box containing identical particles and you want to compute the distances between each particle and every other particle in the box without double-counting (i.e., if you've ...
178 views

### Capturing an F1

I teach an Intro to Mathematica course, and one of the things I try to reinforce early on is just how helpful Mathematica's help is. In the very first lab for the course, I even give the students a ...
188 views

### Performance: Collapsing repeated contiguous rows & cols from a matrix

In this answer I needed to remove contiguous zero-valued cols and rows from a matrix, leaving only two of them in place, no matter what the original number was. I made up this code: ...
123 views

### Solving an equation with rational expressions (step by step) [duplicate]

Consider the following equation with rational expressions: $$\frac{5}{x+4}=4+\frac{3}{x-2}$$ We will look at the plot. We will use the Solve command to check our answer. ...
535 views

### Listing matrices up to symmetry

I am interested in the equivalence relation on N x N binary matrices, in which two matrices are equivalent if one can be obtained by rotating/reflecting the other. I would like to obtain a list ...
409 views

### How to change front end setting “Parallel Kernel Configuration” in the code?

I'm trying to run Mathematica parallel on multiple nodes on a HPC, and I use the remote kernel tab in the "Parallel Kernel Configuration" settings to set the communication between different nodes(...
597 views

### How to dequantify units in mathematica?

Is there a function which applied to a quantity returns its numerical value so I for instance can fill it into my Predictorfunction?
642 views

### Finding minimal distance between two surfaces

This code will display two parametric surfaces: ...
2k views

### Reading in scientific notation from C++ to Mathematica

With a text file with entries formatted as (output from C++): f[38.67] = -2.5387862698183892298317350539374412777263289550697e-05; ⋮ Is there a way to read this ...
610 views

### Summation with constraints

I am trying to do the summation shown below, $\sum_{i_1=0}^{imax_1} \sum_{i_2=0}^{imax_2} \dots \sum_{i_k=0}^{imax_k} f(i_1,\dots,i_k)$ $k$ is a variable. Therefore $i$ and $imax$ are defined as ...