Documentation for pp_lib

Generated by IDLdoc

single page | use frames     summary     class     fields     routine details     file attributes

./

pp_quartile.pro


Routines

top source pp_quartile

result = pp_quartile(iarr, quart [, cut=cut] [, nan=nan] [, index=index] [, sort=sort])

Given an array iarr, returns the value(s) in the array that correspond to the given quartile(s). If cut is set, instead of the quartile values, returns a copy of the array, with minimum and maximum values given by the two quartiles provided.

Parameters

iarr in required

The array for which the quartile(s) will be calculated.

quart in required

The desired quartile(s). It can be a scalar or an array.

Keywords

cut in optional

If set, quart must be a two-element array. Instead of returning quartile values, the function will return a copy of the array, with all values below the low quartile (the first element in quart) will be set to the array's value at that quartile, and all values above the high quartile (the second element in quart) will be set to the value of the high quartile.

nan in optional

If the array contains non-finite values (NaN or Infinity), this must be set so that the quartiles are correctly calculated. By default, it is set. Setting nan to zero saves time, but if the array contains non-finite values and nan is zero, incorrect results may be returned.

index out optional

An array with the index in s corresponding to the quartiles selected. Useful to obtain indices in iarr that match some quartile level. See example

sort out optional

An array with the indices to sort the input array: s=sort(iarr)

Examples

Create an array with 10 values between 0 and 9 and check on some of its quartiles:

a=reverse(dindgen(10)) print,pp_quartile(a,[0.2d0,0.8d0]) ; 2.0000000 8.0000000 print,pp_quartile(a,[0.2d0,0.8d0],/cut) ; 8.0000000 8.0000000 7.0000000 6.0000000 5.0000000 ; 4.0000000 3.0000000 2.0000000 2.0000000 2.0000000 Obtain the elements of a which are below the 50% quartile:
a_50=pp_quartile(a,0.5d0,index=ind,sort=s) print,a[s[0:ind]] ; 0.0000000 1.0000000 2.0000000 3.0000000 4.0000000 5.0000000

Author information

Author:

Paulo Penteado (http://www.ppenteado.net ), Jan/2016

Statistics

Lines:
14 lines
Cyclomatic complexity:
4
Modified cyclomatic complexity:
4

File attributes

Modification date: Wed Jun 29 22:15:28 2016
Lines: 14
Docformat: rst rst