# Nicolas Douillet

### PhD, INRIA and CNRS alumni

Interested in computational geometry, image processing, 3D reconstruction, geometry, mesh processing, mesh generation, number theory, fractals.

**Programming Languages:**

MATLAB

**Spoken Languages:**

English, French

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RANK**7,938**

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**16** Questions

**14** Answers

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RANK**1,463** of 19,433

REPUTATION**1,243**

AVERAGE RATING**5.00**

CONTRIBUTIONS**79** Files

DOWNLOADS **228**

ALL TIME DOWNLOADS**8416**

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CONTRIBUTIONS**0** Public Channels

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**Content Feed**

Submitted

Any rotation (3D, 2D)

Function to rotate a -array of- vector(s) around any given -shifted- axis, in 2D or 3D space.

1 month ago | 12 downloads |

Solved

Construct an index vector from two input vectors in vectorized fashion

Create an index vector defined by two input vectors, one defining the beginnings of one or more index ranges, and the other defi...

2 months ago

Solved

Fill a zeros matrix

The aim is to fill an array of all zeros given a numerical value and the index of row and columns for this value. 3 Inputs: ...

2 months ago

Solved

"Low : High - Low : High - Turn around " -- Create a subindices vector

Let two vectors *lo* and *hi* be given. The job is to create a index vector like so idx = [lo(1):hi(1) lo(2):hi(2) ...]...

2 months ago

Solved

Matrix indexing with two vectors of indices

Given a matrix M and two index vectors a and b, return a row vector x where x(i) = M(a(i),b(i)).

2 months ago

Solved

Sum My Indices

Given inputs M and N (in that order), output an MxN matrix whose entries are equal to the sum of their indices. Example input...

2 months ago

Solved

Getting the indices from a matrix

Inspired by Problem 645. Getting the indices from a matrix. Given a matrix A (or a vector), return the indices (always in row...

2 months ago

Solved

First non-zero element in each column

For a given matrix, calculate the index of the first non-zero element in each column. Assuming a column with all elements zero i...

2 months ago

Solved

Replicate elements in vectors

Replicate each element of a row vector (with NaN) a constant number of times. Examples n=2, A=[1 2 3] -> [1 1 2 2 3 3] ...

2 months ago

Solved

Set the array elements whose value is 13 to 0

Input A either an array or a vector (which can be empty) Output B will be the same size as A . All elements of A equal to 13...

2 months ago

Solved

Getting logical indexes

This is a basic MATLAB operation. It is for instructional purposes. --- Logical indexing works like this. thresh = 4...

2 months ago

Submitted

Isprime optimus [FAST]

Primality test using isprime Matlab(r) stock function, but ~60% faster. Based on Nicolas Douillet 'Christmas eve prime squares e...

2 months ago | 7 downloads |

Submitted

alGolbach

Algorithm to compute and list every Goldbach couples of prime numbers which sum equals the given -even- input

2 months ago | 4 downloads |

Submitted

Prime numbers spirals

Functions to display prime numbers spiral and prime squares spiral. Also check primes sum and prime squares spiral length.

2 months ago | 4 downloads |

Quickest way for alternate indexing a vector

Thank you all for your interest and answers :-) I am going to test them, pick the best in my case, and then choose for the co...

2 months ago | 0

Question

Quickest way for alternate indexing a vector

Hey, I am looking for the quickest way to create a vector like this : u = [5 7 11 13 17 19 23 25 ...

2 months ago | 5 answers | 0

### 5

answersSubmitted

Mesh generation toolbox

Some useful tools for mesh generation

5 months ago | 10 downloads |

Submitted

mesh processing toolbox

Some useful tools for mesh processing

6 months ago | 21 downloads |

Submitted

Sample triangle (2D, 3D, ND)

Function to generate a triangular sampling grid of a given triangle

6 months ago | 5 downloads |

Submitted

Platonic solids

Function to compute and display the five platonic solids.

6 months ago | 1 download |

Submitted

Projective geometry demo

A "pedagogic" demo of projective geometry showing some mathematical objects projections

6 months ago | 2 downloads |

Submitted

Mesh ovoid

Function to compute, display, and save a meshed ovoid

6 months ago | 2 downloads |

Apparent distance conservation in Matlab plot window while rotating 3D objects

Ok I realized I have to be even clearer. I am going to eplore the camera toolbar possibilities -which I didn't really know unti...

7 months ago | 0

Submitted

Apollonian gaskets

Function to compute and display the apollonian gasket of any 3D triangle or 3D regular polygon

7 months ago | 3 downloads |

Submitted

Lines intersection (2D, 3D) [FAST]

A function to compute the intersection point between two lines of the space (3D or 2D)

7 months ago | 2 downloads |

Submitted

Triangle incircle (2D, 3D) [FAST]

Computes and display the incircle coordinates, the centre and the radius of one given 2D or 3D triangle

7 months ago | 1 download |

Submitted

chat with HAL9000 !

chat with HAL9000 and try to survive it ! ^_^

7 months ago | 1 download |

Submitted

Meshed Reuleaux tetrahedron

Function to compute, display, and save a meshed Reuleaux tetrahedron

7 months ago | 1 download |