# All Questions

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### How do I perform the following numerical integration

I have the following integral to evaluate numerically: $$x(t) = \frac{1}{f(t)}\int_0^{t_b} t^m (t + n)^o \sin(pt) \mathrm{d}t \quad m,n,o,p \in \mathbb{R}$$ ...
474 views

### Better way to test that a matrix is upper-triangular?

Today, I got to thinking about how to test that a matrix was upper-triangular. So I had a try at it. Algorithm $\quad \quad a_{ij}=0$ Or $i \leq j$ $\Rightarrow$ $True$ My solution is ...
86 views

### Bug? Side effects when exporting to .mx

I seem to have encountered a bug when exporting to .mx, at least on OS X. Can anyone reproduce this? I am on MMA 10, OS X 10.9.4. ...
97 views

### Why legendmarkers shifted a few pixels after opacity is specified

In below simple graph, if an opacity is specified in the legendmarkers, the plot marker shifted a little bit, can someone please shed some lights? ...
390 views

### How to create a table?

I have looked here at the forum and on the mathematica documentation center though still couldn't get it to work. I have two lists ...
205 views

### How to draw the trajectory of a moving particle

I want to draw a 3D graph showing a nanoparticle movements in liquid environment. Basically,the code is like the followings. I used Table to generate the position coordinates instead of using the ...
310 views

### One to Many Lists Merge

I have two lists: ...
194 views

### Export[] performance

Consider this sequence of commands: ...
94 views

### Defining a function that that evaluates a function to obtain a value not supplied as an optional argument

I have a function like this CentralDifferentMethod[α_, β_, α1_, α2_, λ_, v0_, dt_, t_] Now, I want to add a new parameter ...
135 views

### Rearranging 5 equations

I am trying to rearrange 5 equations in terms of 5 variables. I have the equations for y1, y2, ...
129 views

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315 views

### How to draw multi curves in a graph with errorbars

The curves are composed by several 2*n nested lists. I want these curves be placed in a 3d way, like the xy plane is for the data, different curves are located in several parallel xy planes with ...
84 views

### Import file size capacity for Mathematica

I am trying to import a large data set (.csv) into Mathematica. The data set contains more than 14 million rows, is this something Mathematica can handle? If not, what is the maximum capacity? I have ...
73 views

### How to solve this equation?

Mathematica does not give me the correct solution (-1) for this equation: Solve[9^(x + 4) == 27^(1 - x), x] Do I miss something or is Solve the wrong approach ...
292 views

### Approximation to the prime counting function

Is there a function similar to PrimePi that gives approximate value for large numbers? In particular, I need a reasonably good approximation for $\pi(x)$, where ...
93 views

### How could I visualize a rotating cone within a sphere? [closed]

I am just learning Mathematica. How can I visualize a rotating cone within a sphere? The length of my cone is governed by following equation. ...
137 views

### How can I restore the old ImageCompose behaviour?

Prior to version 10, if ImageCompose was used to overlay a partially transparent image region over a completely transparent image region, the result would keep the ...
77 views

49 views

### distributing definitions in an .m file and memory

I am dealing with a huge table stored in an .m file of size 4 GBs. Somehow when I call the table in .nb file it seems the memory increases not by 4 GBs but more than 10GBs (roughly checking from task ...
60 views

### NMaximize not substutiting parameters of objective function [duplicate]

NMaximize is not substituting parameters of its objective function. Is there a way to fix that? I have a three line program that exhibits the problem. ...
114 views

### Possible bug / numerical issues with HypergeometricU — any suggestions for a fast workaround?

I've encountered some problematic behaviour with HypergeometricU. I have a probability distribution on the positive integers that takes the following form after ...
72 views

### How can I create a set (list) provide a kind of rule/algorithm?

Example: S = {r ∈ Q : r² < 2} Let S be the set of all rational numbers whose squares are less than 2. It follows that 1 ∈ S, 4/3 ∈ S, but 3/2 doesn't ∈ S because 9/4 ≥ 2. Thank you.
190 views

### Graph expansion on Mathematica

Is there a way by which Mathematica can be given a graph as an input and be asked to find its expansion? Note: By "expansion" I mean the quantity called "isoperimetric number" or "Cheeger constant", ...
131 views

### NSolve for complicated equation involving double cross product

I have the following issue. I am trying to solve a 3-vector equation for the vector slx, sly, and ...
408 views

### Greek variables in 10.0.1

Bug introduced in 10.0.1 and fixed in 10.0.2 10.0.1 under Ubuntu 12.04 x64 .... Does everybody get greek variables emboldened? Is anybody aware of how to revert to previous normal display? The ...
222 views

### Solution to a T+U = E equation

I needed to solve really easy differential equation (in dimensionless units):  \mathcal{T} (\dot{\xi}) + \mathcal{U} (\xi) = \text{const.} \equiv \varepsilon ; \quad T(\dot{\xi}) = \dot{\xi}^2 ; ...
77 views

### Bug with Initialization in DynamicModule?

In exploring Tracking Initialization, I came across this. The following usually shows a value for x of 300000 to ...
288 views

### How to plot a series using different colors depending on the y-value

I have a sequence of numbers ${x_1,x_2,\ldots,x_n}$. I would like to plot the sequence using ListLinePlot but use a different color depending on if the values $x_i$ are within $a_i<x_i<b_i$. ...
150 views

### Tracking Initialization

How to track Initialization step by step? Any tricky solution is ok. One condition, x should be ...
602 views

### Extracting the function from InterpolatingFunction object

I've used Interpolation[] to generate an InterpolatingFunction object from a list of integers. ...
245 views

### Find all heads a function is defined on

So say I've got a function g defined as follows: g[x_Integer] := x + 1 g[s_String] := s <> "!!!" How would I write a ...