# All Questions

48 views

### What does F[[1]] mean? [on hold]

I defined a function "F" and checked length, then I wanted to select terms I needed, and failed. One of my friends said I should typed something like that: ...
35 views

### Topics for master's project using Mathematica [on hold]

I wish to do 1 year project in linear algebra using Mathematica. What are linear algebra topics which can be implemented on Mathematica as part of 1 year graduate level dissertation.
94 views

### 4th-order Runge-Kutta method to solve a system of coupled ODEs [duplicate]

I am a beginner at Mathematica programming and with the Runge-Kutta method as well. I'm trying to solve a system of coupled ODEs using a 4th-order Runge-Kutta method for my project work. I have ...
94 views

81 views

### How do I smooth or remove jitter from an exported Graphics3D plot?

I have exported a Graphics3D plot as gif. But the plot shows jitter (You can see the yellow ball shows somewhat slight move around, which is expected to be still). How does this happen and how to get ...
60 views

### DensityPlot and KroneckerDelta

I have the following DensityPlot: DensityPlot[Sin[x] Sin[y], {x, -Pi/4, Pi/4}, {y, -Pi/4, Pi/4}, ColorFunction -> "SunsetColors", PlotLegends -> Automatic] ...
90 views

### Comparing memory consumption of two pieces of code

I have implemented something I want to do in two different ways, because I'm not sure which of the two approaches give best speed/memory efficiency. Comparing the speed of the two approaches is ...
68 views

### Filtering the output from Table and export it into excel

I have the following functions ...
43 views

### Call functions from a notebook inside C#

Is there a way to use functions from a notebook in C# with NETLink ? I found only this: Evaluate Notebook from .Net, but it is not of much help. Any suggestions ?
24 views

### How can i specify a NotebookSelection by a given CellObject?

My Questing is very simple. If I have a CellObject e.g. CellObject[Text], I can move the selection to this ...
36 views

### Problem in deriving general equation [closed]

I have a problem to derive a general equation in Mathematica. The code below supposedly computes the intersection area What modifications should I make to the code to derive the area in terms of ...
52 views

### DatePlus and DayPlus perform much worse than my user-defined-function

I was debugging a function speed, and discovered that the time bottleneck was in DatePlus. I tried to change to DayPlus and get ...
44 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 ...
249 views

### How do I write a condition for Position that uses both the current and previous element?

For example, given {57, 3, 40, 94, 9, 84, 81, 93, 76, 5, 7, 76, 38, 9, 23, 95, 49, 0, 30, 3} I'd like to get all the indices at which the elements cross from ...
29 views

### ListLinePlot will not print all the coordinates. How can I overcome this? [closed]

I have the following list: ...
38 views

### Defining the domain of positive real numbers

I am trying to solve an equation by assuming that all the variables are real and strictly positive. I can use the keyword Reals for the argument ...
350 views

### Turning a set of random walk data 45 degrees

I have a set of data that is just a "random" (generated by me, not by computer) sequence of length 2000 of 1's and (-1)'s. I used it to plot a 1-D random walk where +1 is step up, (-1) is step down, ...
40 views

### Plot 3D with conditions and variables dependent on each other

I m trying to do something like this: ...
44 views

### FindRoot, Loops and multivariate nonlinear system

I posted a question yesterday asking how I could get all the solutions to my system of 4 nonlinear equations with 4 unknowns. I gave up on this since it seems ...
50 views

### If the earth's rotational speed increased by 2% each day starting today…what would be the difference in age 20 years from now? [closed]

If the new adjusted revolution of the earth still equaled one day and 365 days still equaled one year, how old would someone be 20 years from now (20 years based on the current rotation of the earth) ...
28 views

### How to debug an existing notebook in Workbench

I have an existing notebook that I want to debug in workbench. This notebook is a self contained program that does not use any .m files. From what I can tell from the Workbench documentation you ...
23 views

### How to identify primary keys in an existing database table

I would like to identify the primary keys in a DB table using DatabaseLink commands trying to exclude SQLExecute. It seems like SQLTableInformation or SQLColumnInformation may not show that ...
60 views

### Memory Problem with Modules and NDSolve

I'm using NDSolve inside a module, and I appear to have a memory leak. The relevant code is: ...
25 views

### about Updating Wagon's FindAllCrossings2D[] function [closed]

I am working with the shortest version of FindCrossings2D, which was provided by Vitaliy Kaurov. Here is Vitaliy's function: ...
80 views

### Finding R^2 and R^3 of relations [closed]

Let R be the relation on the set { 1 , 2 , 3 , 4 , 5 } containing the ordered pairs (1 , 1) , (1 , 2) , (1 , 3) , (2 , 3) , (2 , 4) , (3 , 1) , (3 , 4) , (3 , 5) , (4 , 2) , (4 , 5) , (5 , 1) , (5 , ...
30 views

### Parallel evaluation hangs before doing anything

[I use Mathematica 9.0.1.0 on OS X Yosemite 10.10.2.] I am experiencing difficulty with parallel evaluation that I am finding extremely perplexing to troubleshoot. I define the following function in ...
130 views

### Get Axes Range of Plot?

Say I have some plot plot = Plot[Sin[x], {x,0,10}] (*as an example*) Is there a way I can get the x and y axes min/max values from the "plot" variable? If I ...
92 views

### Simplified expression is different than original

I have a question regarding the Simplify command in mathematica. I am working with a 4 x 4 table called Eqs, filled with symbolic expressions. I then do ...
131 views

### Mathematica on Raspberry Pi

Can I develop BSD/MIT open-source library for Mathematica using free non-commercial version on Raspberry Pi? To state it differently: does the non-commercial limitation of Mathematica on RPi limit ...