# All Questions

338 views

### Solve telling me all my solutions are zero

I'm trying to use Mathematica to solve a complicated system of equations. Here is a screenshot of the equations, and what Mathematica outputs. The variables $v_i$ and $w_i$ act as constants in ...
287 views

### Resetting an animation with a custom button

I have the following code, which accepts a function via an InputField, and then gradually draws that function in a Plot using ...
288 views

### Log function - why is Log[b,b] not being evaluated to 1?

Have been experimenting with the Log function to demonstrate simple Log relationships such as Log[xy], Log[x+y] etc. ...
254 views

### Retaining and reusing a one-to-one mapping from a sort

Imagine I sort the elements of an array $Q$ by some means. Perhaps I sort strictly by the elements in the first column, perhaps I use SortBy[...] to sequentially sort by the elements in successive ...
160 views

### SQL JDBC Zerodatetime

I am trying to query SQL data with MATHEMATICA - however, the MySQL database contains zerodates and that leads to the following error message: e.g. (1) *SQLSelect[conn, "orders", {"time_created"}, ...
394 views

### How can I make a customized InputField for date inputs?

I want to make an InputField that only allows a specific date format to be entered. I want to display a field hint in the format "dd:mm:yyyy". Once the user clicks ...
356 views

### Is there a “GrabHand” and “OpenHand” MouseAppearance in Mathematica?

MouseAppearance[Plot[Sin[x], {x, 0, 5}], "LinkHand"] Unfortunately I cannot get a screen grab to show the link hand but it is a cartoon hand with a finger ...
208 views

### Summing tensors in mathematica

How do I perform the following summation in mathematica? $$\Sigma_{m=1}^5 e_{ijklm}A^{mn}$$ I have the $e_{ijklm}$ tensor of rank 5 in 5 dimension as a array and $A^{mn}$ ...
2k views

### Mathematica Implementations of the Random Forest algorithm

Is anyone aware of Mathematica use/implementation of Random Forest algorithm?
520 views

### How can I get LineLegend to pick up my plot's BaseStyle?

The new legends functionality in version 9 really simplifies creating legends, and it automatically picks up the styles of the lines. ...
162 views

### Repeating the contents of one cell in another, in “real time”

How could I create two Input cells, such that when the first is evaluated, the contents of the first are copied to the second? So for example, there would be two empty cells - let's call them A and B ...
320 views

### Splicing a list of arguments into a function with Sequence

Not sure if this has been asked, but I have a fairly simple operation that I don't know the syntax for. Say I have an array with some values, and a function f that accepts an arbitrary number of ...
190 views

### Strange Behavior with RegionPlot

Consider the following code. RegionPlot[Print[{x, y}], {x, -2, 2}, {y, -2, 2}, PlotPoints -> 2] ...
267 views

### Wavelets: Relative error vs compression ratio

I need to plot the relative error vs compression ratio diagram of a discrete wavelet transform on an image, but no luck so far .. Here's the problem in short: random_image.jpg compress the image ...
73 views

### How do I eliminate the breaks in a 3D plot with a Max or Min function? [duplicate]

Whenever I make a 3D plot using the Max or Min functions, I get breaks in the plot when it switches from one expression in ...
4k views

### Creating a simulation of our Solar System

As the title says, my objective is to create a simulation of the motion of the planets in our Solar System using Mathematica. All the theoretical background regarding the equations of motion of ...
549 views

### Efficient code for tallying entries in very large lists

I am dealing with data sets containing tens of millions of (hashable) entries and simply using the Tally function to count the frequency of each unique list element ...
353 views

### Converting a list of replacement rules into a list of real values [duplicate]

The following command outputs a list of replacement rules. ...
189 views

### Locator Appearance

I am using LocatorPane with LocatorAutoCreate -> True. I would like to have the appearance of each new locator be different. ...
526 views

### Plotting a 3D list causes kernel to crash if x and y axes have vastly different scales

I have access to two versions of Mathematica, version 7.0.1 on Linux and version 8 on Windows. When I try the following two lines on version 7, the kernel quits when it tries to plot. In version 8 ...
197 views

### Using Outer with Compiled functions that accept more than 2 arguments

How does one use Outer with a compiled function that accepts 3 or more arguments. Alternatively, how does one create a compiled function with 3 or more arguments ...
322 views

### Using mesh for a single function inside Plot

Plot[{Sin[x], Cos[x]}, {x, 0, 10}, Mesh -> {{0, \[Pi]}}, MeshShading -> {Black, Red}] In the above, how can I specify that I want the mesh for just, ...
185 views

### Big spaces between legend positions

I am trying to make a legend for my plot. Actually, I made one, but I cannot understand why there are such big spaces between the legend positions. ...
744 views

### Parametric differentiable interpolation of a 2D data set

I have a set of data ...
3k views

### Why does Mathematica struggle with solving this equation?

Consider the evaluation of the following expression In[20]:= Reduce[ 1000 * 1.0609^t == 1500, t] ...
437 views

### ListLinePlot filling for accumulated data

I have 23 variables (energy production units) which take values for each hour of the day (energy dispatch table). Here is a PasteBin example of data. I am trying to represent the distribution of the ...
255 views

### How can I sequentially apply different graph embeddings?

Imagine I have some graph G, and I perform a graph embedding using a command like: ...
290 views

### Convert BSplineFunction into two Interpolating Functions

Is there a way to decompose a BSplineFunction output into two functions x[t], y[t] ...
154 views

### Extending a plot over a secondary variable

Apologies for the vague title; couldn't really think of a better way of putting it. I have a function $F$ of two variables, $\rho\in[0,\infty)$ and $f\in[0,1]$, that I wish to create a plot over ...
421 views

### Quick multiple selections from a list

What is the fastest way to make multiple selections from a list? Compiled methods included. For example, here are two methods for selecting a subset, compared:- ...
588 views

### What is the difference between prefix/postfix notations and map?

I am new to Mathematica and just experimenting with the different programming constructs. I have been looking at Map and how to evaluate a function for a list of ...
143 views

### Solving an equation for asymptotic dependence of the solution on a coefficient

I have an equation I want to solve, so I entered the following into Mathematica. (x^(17/6))/(a^(17/6)) - (x^2)/a -1 == 0 where I assume $a>>1$ and $x$ is ...
132 views

### How to change variable that has been defined in PDE?

I have a PDE function that contains a variable (named ka). I want to plot the result of my PDE in 1 plot using several different ka values. However, I'm not sure about how to write down this equation. ...
262 views

### How can I retrieve the point coordinates from a LOG Plot after the data points were manually moved?

I'm having problems with getting coordinates out ofa ListLogLogPlot I basically plotted a list, then selected data points on the graph, moved these points around, ...
692 views

### Generating a random walk with defined step size

By the following I'm trying to generate a list of random coordinates (ex. 4) each within unit distance from previous one, starting from origin. What am I doing wrong? ...
243 views

### Eliminate several variables between five Conic_section equations

I want to eliminate x1, x2, y1, y2 between these 5 equations. I tried ...
260 views

### Processing and storing a graph with a large number of vertices s.t. k-hop neighborhoods are efficiently retrievable

I have an unweighted, undirected graph $G$ with $(v_1, ..., v_N) \in V$ vertices, where each vertex in the lattice represents a string of some length ($\leq 200$ characters), and I need to construct ...
305 views

### How can I get an exponent vector from monomials?

I am trying to get an exponent vector from a list of monomials. I am using the CoefficientRules command; however, it is returning a list that includes the ...
212 views

### Embedding Mathematica Console into a Java/.NET Application [duplicate]

I enjoy using Mathematica's notebook interfaces, but more specifically the autocompletion in each notebook. I'm in need of a way to put tons of Mathematica windows on the same page. It would be an ...
275 views

### EventHandler not working within DateListPlot (?)

I have some {date, value} data: data = Transpose[{AbsoluteTime /@ Thread[{2012, Range[12], 15}], RandomInteger[10, 12]}] ...
194 views

### Does new MMA9 Time Series support obsolete the old TimeSeries Package?

MMA9 includes a fair number of functions and symbols that seem to overlap with the old TimeSeries package. The new features are documented here and the old material is documented here. Some of the ...
186 views

### How can I find the points of B Spline functions for a specific range?

Based on this question: I have a list of bspline functions (nearly 1000) provided by applying BSplineFunction to a list of points. I want to get the points each of ...
462 views

### Replacing values of a function

I have recently starting using Mathematica and have recently come to what seems as an impasse in my understanding of the language. If this is too "tell me how to do it" I would certainly understand. ...
193 views

### What is the maximum real value for Compile?

Can one be found programmatically? The function I'm compiling, indicesOfMin, gives the indices of the minimum value(s) of a real-valued list, the parameter, in a ...
403 views

### Has anyone implemented cohomology for complex manifolds?

I'm investigating the cohomology of complex manifolds, and need to construct chain complexes, Mayer-Vietoris sequences etc. I use Mathematica for numerically tracing manifolds with geodesics, but ...
664 views

### Strategies for solving problems involving searches

As an example of a search-oriented problem, consider finding all constrained $n$-colorings of a graph. An "$n$-coloring" associates one of $n \ge 1$ colors to each vertex in such a way that no edge ...
321 views

### How can I change cursor style in InputField?

I want to make an InputField with a horizontal cursor, like this: Note that the blinking cursor should be horizontal and not the mouse pointer! Nevertheless, ...
463 views

### How to Initiate a queued evaluation from a Dynamic GUI without using a Button

I have a Dynamic-based GUI, and one part of it will kick off a calculation that could take longer than the default 5-second dynamic timeout. I know that ...