enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Determining the number of clusters in a data set - Wikipedia

    en.wikipedia.org/wiki/Determining_the_number_of...

    The average silhouette of the data is another useful criterion for assessing the natural number of clusters. The silhouette of a data instance is a measure of how closely it is matched to data within its cluster and how loosely it is matched to data of the neighboring cluster, i.e., the cluster whose average distance from the datum is lowest. [8]

  3. k-means clustering - Wikipedia

    en.wikipedia.org/wiki/K-means_clustering

    [59]: 354, 11.4.2.5 This does not mean that it is efficient to use Gaussian mixture modelling to compute k-means, but just that there is a theoretical relationship, and that Gaussian mixture modelling can be interpreted as a generalization of k-means; on the contrary, it has been suggested to use k-means clustering to find starting points for ...

  4. GNU Octave - Wikipedia

    en.wikipedia.org/wiki/GNU_Octave

    Octave programs consist of a list of function calls or a script. The syntax is matrix-based and provides various functions for matrix operations. It supports various data structures and allows object-oriented programming. [26] Its syntax is very similar to MATLAB, and careful programming of a script will allow it to run on both Octave and ...

  5. Kernel (statistics) - Wikipedia

    en.wikipedia.org/wiki/Kernel_(statistics)

    The first requirement ensures that the method of kernel density estimation results in a probability density function. The second requirement ensures that the average of the corresponding distribution is equal to that of the sample used. If K is a kernel, then so is the function K* defined by K*(u) = λK(λu), where λ > 0. This can be used to ...

  6. Day count convention - Wikipedia

    en.wikipedia.org/wiki/Day_count_convention

    This convention accounts for days in the period based on the portion in a leap year and the portion in a non-leap year. The days in the numerators are calculated on a Julian day difference basis. In this convention the first day of the period is included and the last day is excluded. The CouponFactor uses the same formula, replacing Date2 by Date3.

  7. k-medoids - Wikipedia

    en.wikipedia.org/wiki/K-medoids

    The k-medoids problem is a clustering problem similar to k-means. The name was coined by Leonard Kaufman and Peter J. Rousseeuw with their PAM (Partitioning Around Medoids) algorithm. [ 1 ] Both the k -means and k -medoids algorithms are partitional (breaking the dataset up into groups) and attempt to minimize the distance between points ...

  8. Multivariate normal distribution - Wikipedia

    en.wikipedia.org/wiki/Multivariate_normal...

    Under the null hypothesis of multivariate normality, the statistic A will have approximately a chi-squared distribution with ⁠ 1 / 6 ⁠ ⋅k(k + 1)(k + 2) degrees of freedom, and B will be approximately standard normal N(0,1). Mardia's kurtosis statistic is skewed and converges very slowly to the limiting normal distribution.

  9. Kernel density estimation - Wikipedia

    en.wikipedia.org/wiki/Kernel_density_estimation

    Kernel density estimation of 100 normally distributed random numbers using different smoothing bandwidths.. In statistics, kernel density estimation (KDE) is the application of kernel smoothing for probability density estimation, i.e., a non-parametric method to estimate the probability density function of a random variable based on kernels as weights.