pct

Format: pct( list, percent )

Arguments: [real] list Input list

[real] percent Optional percentile to locate in the range 0 to 1, default = 0.5

Returns: (any) The element in list located at the percent percentile

Description: Pct locates the element in a list of input data that falls on the specified percentile. This primitive can be used like min, med, and max to determine the range or central value of a list of experimental data. Unlike these primitives, though, pct allows you to specify the specific percentile you wish to find. If the percentile you wish to locate lies between two elements in list, pct returns the average of the two.

Examples: pct(list,[0,0.5,1]) = minimum, median, and maximum values in list

pct(list,[5%,95%]) = the range containing the central 90% of all data in list

x:=0..[100%,2%]

graph(x,pct(list,x)) = creates a cumulative distribution graph of the data in list