StandardDeviation (GenericNamedArraylist function): Difference between revisions

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==Examples==
==Examples==
This request calculates the standard deviation of the items in a <var>NamedArraylist</var>:
<p class="code">b
<p class="code">b
%nl is namedarrayList of float
%nl is namedarrayList of float

Revision as of 19:54, 16 July 2012

Calculate standard deviation of items or function of items (FloatNamedArraylist, NamedArraylist, and UnicodeNamedArraylist classes)

[Introduced in Sirius Mods 7.8]


This method returns by default the standard deviation of the values of the items in the collection, or the standard deviation after a specified function has been applied to the items.

The standard deviation measures the variation from the mean of the collection items; it is the square root of the collection's variance.

Syntax

%number = anyNal:StandardDeviation[( [itemFunction])]

Syntax terms

%number A Float variable to contain the numeric result.
anyNal A FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist object.
itemFunction A function that operates on the type of the items in the collection. It may be a local method or method variable or a class member (Variable, Property), and it must return an intrinsic (probably Float) value.

The default itemFunction value is the special identity function, This, which simply returns the item value.

Usage notes

Examples

This request calculates the standard deviation of the items in a NamedArraylist:

b %nl is namedarrayList of float %nl = new %nl('April') = 3000 %nl('May') = 5000 %nl('June') = 8000 printText {~} is {%nl:standardDeviation} end

The result is:

%nl:standardDeviation is 2054.80466765633

See also