Top new questions this week:

How can I draw a 3D cross-section of a 3-torus embedded in 4D Euclidean space?

I have a $3$-torus ($\mathbf S^1\times\mathbf S^1\times \mathbf S^1$) embedded in 4D Euclidean space. How can I draw the cross-section of this $3$-torus cut by a 3D Euclidean space in an arbitrary …

plotting graphics visualization

asked by Shenghan Jiang 15 votes answered by Silvia 17 votes

How to detect crosses and circles in 60x60 raster images?

I have hand-written 60 pixel times 60 pixel squares. I need to detect whether they are empty, x or circle. TextRecognize function fails. Is there some other function to process this kind of raster …

graphics image-processing ocr

asked by hhh 14 votes answered by Mr.Wizard 22 votes

Find continuous sequences inside a list

I have a list which is something like this: {3,4,5,6,7,10,11,12,15,16,17,19,20,21,22,23,24,42,43,44,45,46} What I'd like to to is get the intervals which are in a "continuous" sequence, something …

list-manipulation

asked by mag 12 votes answered by halirutan 25 votes

What technical obstacles prevent all Mathematica code compiling to C

The following represents an attempt at a very simple view of the levels in Mathematica code: We have had lots of questions about deployment and compiling Mathematica code to C. Some of these for …

compile deployment

asked by Jagra 12 votes

Optimizing a Numerical Laplace Equation Solver

Laplace's Equation is an equation on a scalar in which, given the value of the scalar on the boundaries (the boundary conditions), one can determine the value of the scalar at any point in the region …

differential-equations performance-tuning numerical-integration numerics

asked by Vincent Tjeng 11 votes answered by ruebenko 9 votes

Finding Local Minima / Maxima in Noisy Data

I'm trying to find local minima / maxima in noisy data, consisting of data values taken at certain time intervals. Ideally, the function should take a pair of lists (one containing time values and one …

list-manipulation performance-tuning mathematical-optimization

asked by Vincent Tjeng 10 votes answered by s.s.o 4 votes

Going full functional (Haskell style)

I'm trying to define some notation so that Mathematica code would be more functional, similar to Haskell (just for fun): currying, lambdas, infix operator to function conversion, etc.. And I have some …

functional-style custom-notation notation-package

asked by swish 10 votes answered by Mr.Wizard 8 votes

Greatest hits from previous weeks:

Help find a bright object on Mars!

In today's news, scientists found a bright object on one of Curiosity's photos (it's near the bottom of the picture below). It's a bit tricky to find - I actually spent quite some time staring at the …

image-processing

asked by Victor K. 131 votes answered by nikie 157 votes

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't …

reference-request programming

asked by J. M. 188 votes answered by Faysal Aberkane 179 votes

Can you answer these?

Mathematica Functions from VBA

I'm trying to call Mathematica functions from VBA (Excel) using .NETLink without success. (Yes, I know Mathematica Link for Excel exists. And yes, I know the proper thing to do is buy it. However, …

excel .netlink

asked by kale 4 votes

Quantity and Trig functions

I have a bunch of data to which I've assigned units using Quantity, including some angular measurements in degrees. I'd like to be able to use these measurements with trigonometric functions, but it …

version-9 units

asked by David Skulsky 4 votes

looking for a generalised Hough Transform function or a least a function to locate circles

I am looking for a generalised Hough Transform function or a least a function to locate circles (position of center and radius) in a image. There is the standard Hough line search function …

image-processing

asked by Lorenz Mueller 2 votes