enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Group by (SQL) - Wikipedia

    en.wikipedia.org/wiki/Group_by_(SQL)

    Typically, grouping is used to apply some sort of aggregate function for each group. [1] [2] The result of a query using a GROUP BY statement contains one row for each group. This implies constraints on the columns that can appear in the associated SELECT clause. As a general rule, the SELECT clause may only contain columns with a unique value ...

  3. Quantile function - Wikipedia

    en.wikipedia.org/wiki/Quantile_function

    Quantile functions are used in both statistical applications and Monte Carlo methods. The quantile function is one way of prescribing a probability distribution, and it is an alternative to the probability density function (pdf) or probability mass function, the cumulative distribution function (cdf) and the characteristic function.

  4. Q–Q plot - Wikipedia

    en.wikipedia.org/wiki/Q–Q_plot

    Q–Q plot for first opening/final closing dates of Washington State Route 20, versus a normal distribution. [5] Outliers are visible in the upper right corner. A Q–Q plot is a plot of the quantiles of two distributions against each other, or a plot based on estimates of the quantiles.

  5. Quantile regression - Wikipedia

    en.wikipedia.org/wiki/Quantile_regression

    Quantile regression is a type of regression analysis used in statistics and econometrics. Whereas the method of least squares estimates the conditional mean of the response variable across values of the predictor variables, quantile regression estimates the conditional median (or other quantiles) of the response variable.

  6. Quartile - Wikipedia

    en.wikipedia.org/wiki/Quartile

    The first quartile (Q 1) is defined as the 25th percentile where lowest 25% data is below this point. It is also known as the lower quartile. The second quartile (Q 2) is the median of a data set; thus 50% of the data lies below this point. The third quartile (Q 3) is the 75th percentile where

  7. Quartile coefficient of dispersion - Wikipedia

    en.wikipedia.org/wiki/Quartile_coefficient_of...

    Since it is based on quantile information, it is less sensitive to outliers than measures such as the coefficient of variation. As such, it is one of several robust measures of scale. The statistic is easily computed using the first (Q 1) and third (Q 3) quartiles for each data set. The quartile coefficient of dispersion is: [1]

  8. Logistic distribution - Wikipedia

    en.wikipedia.org/wiki/Logistic_distribution

    The inverse cumulative distribution function (quantile function) of the logistic distribution is a generalization of the logit function. Its derivative is called the quantile density function. They are defined as follows: (;,) = + ⁡ ().

  9. Quantile normalization - Wikipedia

    en.wikipedia.org/wiki/Quantile_normalization

    In statistics, quantile normalization is a technique for making two distributions identical in statistical properties. To quantile-normalize a test distribution to a reference distribution of the same length, sort the test distribution and sort the reference distribution.