Sleep related groaning, also called catathrenia, causes you to groan vocally while you sleep. Sleep related groaning is a long-lasting disorder that often occurs nightly. The groaning sound is usually quite loud. Your breathing becomes unusually slow during a groaning episode. You take in a slow, deep breath.
The Gini coefficient (or Gini ratio) is a summary statistic of the Lorenz curve and a measure of inequality in a population.he Gini coefficient (or Gini ratio) is a summary statistic of the Lorenz curve and a measure of inequality in a population.
Definition of correlation coefficient. : a number or function that indicates the degree of correlation between two sets of data or between two random variables and that is equal to their covariance divided by the product of their standard deviations.