Here, by default both apt-cache and aptitude search for a package on whole list of packages in repository, but output of aptitude shows whether the package is installed on the system or not by giving a per-package flag which here is 'p' indicating that package is present but not installed and 'i' which indicates that the package is installed, whereas apt-cache just lists the package and its one-line detail without telling if package is installed or not.
deviation deÂ·viÂ·aÂ·tion (dÄ'vÄ-Ä'shÉn) n. A turning away or aside from a normal course. An abnormality. Deviant behavior or attitudes. The difference, especially the absolute difference, between one number in a set and the mean of the set.
The mean deviation (also called the mean absolute deviation) is the mean of the absolute deviations of a set of data about the data's mean.For a sample size, the mean deviation is defined by. (1). where is the mean of the distribution. The mean deviation of a list of numbers is implemented in the Wolfram Language as.he mean deviation (also called the mean absolute deviation) is the mean of the absolute deviations of a set of data about the data's mean. For a sample size, the mean deviation is defined by.