2,951
edits
Less than: Difference between revisions
Jump to navigation
Jump to search
Merge Boolean sections
(Merge Boolean sections) |
|||
| Line 1: | Line 1: | ||
{{Main|Comparison function}} | {{Main|Comparison function}} | ||
{{Built-in|Less than|<nowiki><</nowiki>}} is a [[comparison function]] which tests whether the left [[argument]] is [[Tolerant comparison|tolerantly]] less than and not equal to the right argument, returning 1 if this is the case and 0 otherwise. It is the [[Not|negation]] of [[Greater than or Equal to]] (<source lang=apl inline>≥</source>). | {{Built-in|Less than|<nowiki><</nowiki>}} is a [[comparison function]] which tests whether the left [[argument]] is [[Tolerant comparison|tolerantly]] less than and not equal to the right argument, returning 1 if this is the case and 0 otherwise. It is the [[Not|negation]] of [[Greater than or Equal to]] (<source lang=apl inline>≥</source>). Less-than [[Scan]], which leaves only the first 1 in its argument set<ref>[[Phil Last|Last, Phil]]. [http://archive.vector.org.uk/art10501140 "Boolean Reductions"]. [[Vector Journal]] volume 26, number 1. 2013-09.</ref>, is a notable pattern. | ||
== Boolean function == | |||
When the arguments to Less than are [[Boolean]], it is the [[wikipedia:converse nonimplication|converse nonimplication]] [[Boolean function]]: | |||
{|class=wikitable style="margin:1em auto" | |||
When the arguments to Less than are [[Boolean]], it is the [[wikipedia:converse nonimplication|converse nonimplication]] function: | |||
{|class=wikitable | |||
!<source lang=apl inline><</source>!!<source lang=apl inline>0</source>!!<source lang=apl inline>1</source> | !<source lang=apl inline><</source>!!<source lang=apl inline>0</source>!!<source lang=apl inline>1</source> | ||
|- | |- | ||
| Line 21: | Line 15: | ||
|<source lang=apl inline>0</source>||<source lang=apl inline>0</source> | |<source lang=apl inline>0</source>||<source lang=apl inline>0</source> | ||
|} | |} | ||
It returns 1 only if the left argument is 0 and the right argument is 1, and is identical to [[Residue]]. Considered as a logical operation, it can be read as ''isn't, as opposed to''. | |||
Less-than [[Scan]] on a Boolean [[vector]] returns a vector which indicates the position of the first 1 in the argument, if any: | |||
<source lang=apl> | |||
<\ 0 0 1 0 0 0 1 0 | |||
0 0 1 0 0 0 0 0 | |||
</source> | |||
It is idiom 348, "First one", in the [[FinnAPL idiom library]]. | |||
== External links == | == External links == | ||
| Line 31: | Line 32: | ||
* J [http://www.jsoftware.com/help/dictionary/d010.htm Dictionary], [https://code.jsoftware.com/wiki/Vocabulary/lt#dyadic NuVoc] | * J [http://www.jsoftware.com/help/dictionary/d010.htm Dictionary], [https://code.jsoftware.com/wiki/Vocabulary/lt#dyadic NuVoc] | ||
== References == | |||
<references /> | |||
{{APL built-ins}} | {{APL built-ins}} | ||