John D'Errico
Retired
A retired applied mathematician, consultant, sometime mechanical engineer, numerical analyst, woodworker, bridge player. Please DON'T contact me, as too many students then decide I am their personal consultant if I allow it. I won't do consulting by mail.
Statistics
62 Files
Cody HighlightsRANK
10
of 290 181
REPUTATION
21 233
CONTRIBUTIONS
15 Questions
7 522 Answers
ANSWER ACCEPTANCE
46.67%
VOTES RECEIVED
4 598
RANK
4 of 19 676
REPUTATION
64 850
AVERAGE RATING
4.80
CONTRIBUTIONS
62 Files
DOWNLOADS
1260
ALL TIME DOWNLOADS
584353
CONTRIBUTIONS
0 Posts
CONTRIBUTIONS
0 Public Channels
AVERAGE RATING
CONTRIBUTIONS
1 Highlight
AVERAGE NO. OF LIKES
8
Feeds
Solved
Divisible by 2
This is the first problem in a set of "divisible by x" problems. You will be provided a number as a string and the function you ...
nästan 3 år ago
Solved
Edges of a n-dimensional Hypercube
Return the number of edges on an <http://en.wikipedia.org/wiki/Hypercube _n_-dimensional hypercube> (with an integer n ≥ 0). ...
ungefär 6 år ago
Solved
Dots in a Circle
Return how many integer grid points there are inside a circle of radius _r_ centred at (0,0) (including points on the edge). ...
ungefär 6 år ago
Solved
The average of the second largest values
Given a matrix, find the average of the second largest values in each row. The same value does not exist on a row. Example: ...
ungefär 6 år ago
Solved
Fibonacci-Sum of Squares
Given the Fibonacci sequence defined by the following recursive relation, * F_n = F_(n-1) + F_(n-2) * where F_0 = 0 and F_1 ...
ungefär 6 år ago
Solved
Volume of a Simplex
Return the volume of a <http://en.wikipedia.org/wiki/Simplex regular _n_-simplex> with a unit side length. Results are up to...
ungefär 6 år ago
Solved
Volume difference between Ellipsoid and Sphere
Given an ellipsoid of semi principal axis (a,b,c) find the volume of the difference between this ellipsoid and the sphere with...
ungefär 6 år ago
Solved
Perimeter
Given a sequence of points forming a closed path (first and last points are coincident) return the perimeter value. For example...
ungefär 6 år ago
Solved
Return the Fibonacci Sequence
Write a code which returns the Fibonacci Sequence such that the largest value in the sequence is less than the input integer N. ...
ungefär 6 år ago
Solved
Find nearest prime number less than input number
Find nearest prime number less than input number. For example: if the input number is 125, then the nearest prime number whi...
ungefär 6 år ago
Solved
sum of non-primes
The sum of the non-primes no larger than 10 is 1+4+6+8+9+10=38 Find the sum of all the positive non-prime integers that do no...
ungefär 6 år ago
Solved
Extra safe primes
Did you know that the number 5 is the first safe prime? A safe prime is a prime number that can be expressed as 2p+1, where p is...
ungefär 6 år ago
Solved
Pernicious Anniversary Problem
Since Cody is 5 years old, it's pernicious. A <http://rosettacode.org/wiki/Pernicious_numbers Pernicious number> is an integer w...
ungefär 6 år ago
Solved
Get linearly independent vectors of given matrix.
Get a set of linearly independent vectors from the rows of a given matrix. Example matrix=[ 3 -1 0 0 ; ...
mer än 7 år ago
Problem
Euclidean distance from a point to a polynomial
A not uncommon problem in the area of computational geometry is to find the closest point to a straight line from a given point,...
mer än 7 år ago | 3 | 28 solvers
Solved
For given xx,x, y vectors build spline of x and y and find yy values for xx vector.
For given xx,x, y vectors build spline of x and y and find yy values for xx vector. Example x = [ 1.0000 1.5000 2.00...
mer än 7 år ago
Solved
What's size of TV?
Many people buy TV. Usually they ask about diagonal. But also important are width and height. Let's assume that all TV have rati...
mer än 7 år ago
Problem
Euclidean inter-point distance matrix
The Euclidean distance between two points in a p-dimensional space is a really common thing to compute in the field of computati...
mer än 7 år ago | 1 | 24 solvers
Solved
Prime number removal
remove all prime numbers from the input e.g. input = 1 2 3 4 5 6 7 8 9 10 11 12 ...
mer än 7 år ago
Solved
Determine the roots of a cubic equation
Given the coefficients a, b, c, and d of a cubic equation, a*x^3 + b*x^2 + c*x + d = 0, determine its roots.
mer än 7 år ago
Solved
Roots of a quadratic equation.
Calculate the roots of a quadratic equation, given coefficients a, b, and c, for the equation a*x^2 + b*x + c = 0.
mer än 7 år ago
Solved
Sum of digits of powers of 2
Given n, first, calculate the number 2^n. Then, sum the digits that comprise that number. For example: Input: n = 7 2^n = ...
mer än 7 år ago
Problem
Simpsons's rule (but not Homer Simpson)
I wonder what Homer Simpson would have thought of Simpson's rule? Somehow I doubt his thoughts would have included the phrase Ne...
mer än 7 år ago | 4 | 36 solvers
Solved
Right and wrong
Given a vector of lengths [a b c], determines whether a triangle with those sides lengths is a right triangle: <http://en.wikipe...
mer än 7 år ago
Solved
Make a Palindrome Number
Some numbers like 323 are palindromes. Other numbers like 124 are not. But look what happens when we add that number to a revers...
mer än 7 år ago
Solved
Solve the Sudoku Row
*Description* A simple yet tedious task occurs near the end of most Sudoku-solving algorithms, computerized or manual. The ta...
mer än 7 år ago
Solved
Sums of cubes and squares of sums
Given the positive integers 1:n, can you: 1. Compute twice the sum of the cubes of those numbers. 2. Subtract the square...
mer än 7 år ago
Problem
Sums of cubes and squares of sums
Given the positive integers 1:n, can you: 1. Compute twice the sum of the cubes of those numbers. 2. Subtract the square...
mer än 7 år ago | 9 | 241 solvers
Solved
Project Euler: Problem 6, Natural numbers, squares and sums.
The sum of the squares of the first ten natural numbers is, 1^2 + 2^2 + ... + 10^2 = 385 The square of the sum of the first ...
mer än 7 år ago
Solved
Determine Whether an array is empty
Input a matrix x, output y is TRUE if x is empty, otherwise FALSE.
mer än 7 år ago