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31
votes
2answers
6k views

Image Shadow Removal in Mathematica

The task is: Image shadow removal is an important topic in image processing. If you feel curious about it, you may take a look here, or just google for it image shadow removal There are also a ...
27
votes
2answers
1k views

Playing with Matrix falling code in Mathematica

I was trying to create a Matrix falling code image with Mathematica. Here is my code: ...
17
votes
4answers
1k views

How to create effect like Van Gogh's stroke brush?

I need to apply Van Gogh's stroke brush effect to a random image Take the following image as an example: Thank you so much if you could help!
13
votes
2answers
214 views

Convert spectral distribution to RGB color

Presume I have a spectrum as a function of wavelength (an example being the blackbody spectrum): I want to convert that to a single RGB color to display on-screen, i.e. the "color" of that object ...
13
votes
2answers
545 views

How to perform fuzzy lookup between lists?

I have two big lists with 10,000 lines each, with product names from different databases. They have a lot of common products (50%), but they are not typed in the same way. For example there is one ...
11
votes
4answers
569 views

List comprehension in Mathematica

Python supports a concept called "list comprehensions". Following is sample example ...
10
votes
3answers
673 views

Extract connected components from PNG image file and write to individual PNG files

Given the PNG image below with the three leaves in it, I'd like to extract each individual leaf and write it to its own PNG file, using Mathematica 9. Note that in the original image, the box bounding ...
7
votes
5answers
285 views

Making a table with elements like {10i+j, i, j}

Table[10i+j,{i,4},{j,3}] will generate a table that looks like this: {{11,12,13},{21,22,23},{31,32,33},{41,42,43}} I would like ...
7
votes
4answers
387 views

How to set Block local variables by code?

I need to create a user defined Block function where the Block variables values are defined by code. For example, imagine I have: ...
7
votes
3answers
303 views

Composition of mappings not working as expected

I have two functions $f,g:\mathbb{R}^2 \to \mathbb{R}^2$ and I define a third one $h:\mathbb{R}^2 \to \mathbb{R}^2$ as the composition $$h(x,y) = g(f(x,y))$$ I'm trying to get this function into ...
7
votes
1answer
528 views

How can this type of optical illusion be created in Mathematica?

I see these around the web and would like to make them in Mathematica. Combining them in an array is actually quite mesmerizing!
6
votes
2answers
608 views

Distribution of 10 points within a unit square

Related to some packing problems, following problem arose: Distribute 10 points within a square of sides 1, so that minimal distance between them is maximized. With the help of random simulation, or ...
5
votes
1answer
170 views

How to generate nonperiodic tilings?

I need to generate nonperiodic tilings which are similar to the attached figure (kite-domino tiling). I was thinking the code is similar to the code for the Penrose tiling. However, that code is too ...
5
votes
2answers
258 views
4
votes
3answers
1k views

Lyapunov Exponent

Does anyone know a (simple) Mathematica code for computing the Lyuponov Exponent for the Rossler System? Thank you Rossler System: ...
4
votes
1answer
403 views

Tooltip for a ListPlot3D

I am getting stuck with figuring out how to use Tooltip for a ListPlot3D. Basically I have a list of values for the 3D plot (no ...
4
votes
3answers
114 views

Help with coding triangular nodes/elements

I'm trying to write a program where it will shoot out the triangle node numbers. For example, in the picture, if we choose to divide this triangle by 5 points, then the program will return out the ...
4
votes
1answer
362 views

How to implement Kemeny-Young method? (rank aggregation problem)

Prehistory I am trying to make some statistical analysis of some experimental data, arises from measurements made ​​on an ordinal scale. I faced with the problem of rank aggregation: to get from ...
3
votes
6answers
781 views

Getting a String from a list of strings

Is there a way to write down Mathematica with a string such as: {"M","a","t","h","e","m","a","t","i","c","a"}?
3
votes
1answer
4k views

Mathematica code for Bifurcation Diagram

At the moment I am trying to construct a bifurcation diagram of the iterative function $f(x)=$ $ax-1.1975x^3$. I've scoured the internet for pre-made bifurcation diagrams and found many (mostly of the ...
2
votes
6answers
150 views

Setting the elements of a list equal to elements of a different list

A = {a,b,c,d,e,f,g,h} B = {1,2,3,4,5} How would I go about setting some of the elements in list A equal to the elements in list B and then the left over elements ...
2
votes
2answers
2k views

Faster way to convert real strings into numbers [duplicate]

Working with big files, I have to convert some numbers that are in string format into real MMA numbers. I know that I can use ToExpression but it's slow when ...
2
votes
1answer
691 views

How do I hide some of Input

I have a project with a friend, and we make some work in Mathematica. He is not very good at Mathematica, and I have made some long necessary formulas we need. I would like to show what I've made but ...
1
vote
0answers
53 views

Linearised Einstein equations

I need to compute the linearised Einstein Equations around a fixed metric $g_{μν}=\text{Minkowski metric} + h_{μν}$, which is not the flat metric. Does anyone know a Mathematica package or a review ...
1
vote
0answers
63 views

Solving for a charge distribution from a dipole moment [closed]

I've been looking around but I haven't been able to find any way of solving this conceptually simple problem. In short I am trying to find the charge density in a dielectric in an external electric ...
0
votes
1answer
366 views

Use de Casteljau algorithm to create Bezier Curve in Mathematica [closed]

Is anyone can tell me how to create Bezier Curve with given Bezier polygon and parameter t by using de Casteljau algorithm (not the Bezier function in Mathematica)in Mathematica code? Thanks a lot!
0
votes
1answer
158 views

curve on the surface [closed]

I have a bezier polygon aa=Table[{i^2.5, 2*Sqrt[i]}, {i, 1, 5}],is anyone can give me a example in Mathematica code that how to create another iso parametric curve on this bezier surface?Display the ...
0
votes
2answers
45 views

Extracting solutions from one equation and placing them as inputs of another equation [closed]

I have a very simple equation 2x + y = 10 I want to know which integer combinations of x and ...
0
votes
1answer
41 views

Any code to add elements of a list to make a new list? [closed]

Is there any code built in to add the numbers in a list sequentially? For example, lets say I have a list B. B has 6 numbers like below. B={0,6,5,4,3,2} I ...
0
votes
3answers
258 views

Differential equation of mass spring system with compliant stoppers

I would like to solve numerically the differential equation for the displacement x[t] of a mass m-spring ...
0
votes
0answers
77 views

Converting code from Matlab to Mathematica

I have the following piece of code: ...
0
votes
0answers
92 views

step by step interactive indefinite integral

WolframAlpha can give step by step solution for indefinite integral. There seems to be similar question but for derivatives. Is there a way that I can generate my own step by step solution for ...
-1
votes
1answer
88 views

how to extract a subinterval from a previous element in a list (in condition) [closed]

question: i need to use mathematica to write an intermediate value theorem's algorithm, but i don't know how to write in a module form... i have a function and then, we need to set up a range and ...