isMost

isMost is a term used in programming and data analysis to denote a predicate or function that tests whether a given value is the most frequent item in a dataset, i.e., a mode. It is not a universal built-in function in any standard language, but a common naming convention in examples and libraries for working with frequency data.

Formal definition: Given a multiset D of elements and an element x in D, isMost(D, x) is true if the count of x equals the maximum count among all distinct elements in D. If several values share the maximum frequency, each such value satisfies isMost. In pseudocode: counts = tally(D); maxCount = max(counts.values()); return counts[x] == maxCount.

Example: D = [1,2,2,3,2,3,3] has counts {1:1, 2:3, 3:2}; maxCount = 3. isMost(D, 2) is true; isMost(D, 3) is false; isMost(D, 1) is false. If D = [1,2,3,1,2,3], all three values are isMost.

Variants and usage: isMost is often used when identifying commonly occurring items or when computing modal values. It is related to the concept of the mode and can be implemented with frequency counts. Complexity is typically O(n) time and O(k) space, where n is the size of D and k the number of distinct elements.

See also: mode, frequency distribution, modal value, most frequent element.