When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. k-means clustering - Wikipedia

    en.wikipedia.org/wiki/K-means_clustering

    The classical k-means algorithm and its variations are known to only converge to local minima of the minimum-sum-of-squares clustering problem defined as ⁡ = ‖ ‖. Many studies have attempted to improve the convergence behavior of the algorithm and maximize the chances of attaining the global optimum (or at least, local minima of better ...

  3. Square pyramidal number - Wikipedia

    en.wikipedia.org/wiki/Square_pyramidal_number

    In mathematics, a pyramid number, or square pyramidal number, is a natural number that counts the stacked spheres in a pyramid with a square base. The study of these numbers goes back to Archimedes and Fibonacci. They are part of a broader topic of figurate numbers representing the numbers of points forming regular patterns within different shapes.

  4. Legendre's three-square theorem - Wikipedia

    en.wikipedia.org/wiki/Legendre's_three-square...

    In mathematics, Legendre's three-square theorem states that a natural number can be represented as the sum of three squares of integers. if and only if n is not of the form for nonnegative integers a and b. The first numbers that cannot be expressed as the sum of three squares (i.e. numbers that can be expressed as ) are. 7, 15, 23, 28, 31, 39 ...

  5. Pythagorean triple - Wikipedia

    en.wikipedia.org/wiki/Pythagorean_triple

    A Pythagorean triple consists of three positive integers a, b, and c, such that a2 + b2 = c2. Such a triple is commonly written (a, b, c), a well-known example is (3, 4, 5). If (a, b, c) is a Pythagorean triple, then so is (ka, kb, kc) for any positive integer k. A triangle whose side lengths are a Pythagorean triple is a right triangle and ...

  6. Weighted least squares - Wikipedia

    en.wikipedia.org/wiki/Weighted_least_squares

    t. e. Weighted least squares (WLS), also known as weighted linear regression, [1][2] is a generalization of ordinary least squares and linear regression in which knowledge of the unequal variance of observations (heteroscedasticity) is incorporated into the regression. WLS is also a specialization of generalized least squares, when all the off ...

  7. Pell number - Wikipedia

    en.wikipedia.org/wiki/Pell_number

    The left side of this identity describes a square number, while the right side describes a triangular number, so the result is a square triangular number. Falcón and Díaz-Barrero (2006) proved another identity relating Pell numbers to squares and showing that the sum of the Pell numbers up to P 4n +1 is always a square:

  8. Sum of squares - Wikipedia

    en.wikipedia.org/wiki/Sum_of_squares

    The squared Euclidean distance between two points, equal to the sum of squares of the differences between their coordinates. Heron's formula for the area of a triangle can be re-written as using the sums of squares of a triangle's sides (and the sums of the squares of squares) The British flag theorem for rectangles equates two sums of two squares.

  9. Integer partition - Wikipedia

    en.wikipedia.org/wiki/Integer_partition

    Partitions of n with largest part k. In number theory and combinatorics, a partition of a non-negative integer n, also called an integer partition, is a way of writing n as a sum of positive integers. Two sums that differ only in the order of their summands are considered the same partition.