System Variable IO - Revision history

Sudleyplace at 17:50, 16 April 2018

2018-04-16T17:50:45Z

← Older revision		Revision as of 13:50, 16 April 2018
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	<h1><~~apl~~>~~{quad}IO~~</~~apl~~> - Index Origin</h1>		<h1><aplxx>⎕IO</aplxx> - Index Origin</h1>
	{{BoxStart\|<apll>Z←⎕IO</apll>		{{BoxStart\|<apll>Z←⎕IO</apll>
	\| returns the current value of the Index Origin. }}		\| returns the current value of the Index Origin. }}
	{{BoxEnd\|<apll>Z</apll> is an integer ~~vector~~ containing the current value of ⎕IO. This is the lowest value of an array subscript, and is either 1 or 0.}}<br/>		{{BoxEnd\|<apll>Z</apll> is an integer scalar containing the current value of <apll>⎕IO</apll>. This is the lowest value of an array subscript, and is either <apll>1</apll> or <apll>0</apll>.}}<br/>

	{\| border="1" cellpadding="5" cellspacing="0" rules="none" summary=""		{\| border="1" cellpadding="5" cellspacing="0" rules="none" summary=""
	\|\| <apll>⎕IO←0</apll> \|\| ~~set~~ the lowest subscript of an array to 0.		\|\| <apll>⎕IO←0</apll> \|\| sets the lowest subscript of an array to <apll>0</apll>
	\|-		\|-
	\| valign="top" \|<apll>⎕IO←1</apll> \|\| sets the lowest subscript ~~for arrays~~ to 1		\| valign="top" \|<apll>⎕IO←1</apll> \|\| sets the lowest subscript of an array to <apll>1</apll>
	\|-		\|-
	\|}		\|}
	<br />		<br />
	⎕IO determines the lowest subscript for arrays. The default is 1, but can be changed to 0. If an attempt is made to set ⎕IO to a value higher than 1, it is set to 1. If an attempt is made to set ⎕IO to a value ~~loweer~~ than 0, it is set to 0. Setting ⎕IO to anything other than a number causes a DOMAIN ERROR.		<apll>⎕IO</apll> determines the lowest subscript for arrays. The default is <apll>1</apll>, but can be changed to <apll>0</apll>. If an attempt is made to set <apll>⎕IO</apll> to a value higher than <apll>1</apll>, it is set to <apll>1</apll>. If an attempt is made to set <apll>⎕IO</apll> to a value lower than <apll>0</apll>, it is set to <apll>0</apll>. Setting <apll>⎕IO</apll> to anything other than a number causes a <apll>DOMAIN ERROR</apll>.

	<pre>		<apll><pre>
	⎕IO ⍝ default ⎕IO ~~(quad IO)~~ is 1 in a clear workspace		⎕IO ⍝ default ⎕IO is 1 in a clear workspace
	1		1
	⍳5 ⍝ iota 5		⍳5 ⍝ iota 5
	1 2 3 4 5		1 2 3 4 5

	⎕IO←0 ⍝ Set index origin ⎕IO to 0 ~~(zero)~~		⎕IO←0 ⍝ Set index origin ⎕IO to 0

	⍳5 ⍝ iota 5 again but compare the results just below to just above		⍳5 ⍝ iota 5 again but compare the results just below to just above
	0 1 2 3 4		0 1 2 3 4
	</pre>		</pre></apll>

	{{System Variables}}		{{System Variables}}
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Robert Wallick: example of changing quad IO

2016-02-08T19:45:42Z

example of changing quad IO

← Older revision		Revision as of 15:45, 8 February 2016
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	⎕IO determines the lowest subscript for arrays. The default is 1, but can be changed to 0. If an attempt is made to set ⎕IO to a value higher than 1, it is set to 1. If an attempt is made to set ⎕IO to a value loweer than 0, it is set to 0. Setting ⎕IO to anything other than a number causes a DOMAIN ERROR.		⎕IO determines the lowest subscript for arrays. The default is 1, but can be changed to 0. If an attempt is made to set ⎕IO to a value higher than 1, it is set to 1. If an attempt is made to set ⎕IO to a value loweer than 0, it is set to 0. Setting ⎕IO to anything other than a number causes a DOMAIN ERROR.

			<pre>
			⎕IO ⍝ default ⎕IO (quad IO) is 1 in a clear workspace
			1
			⍳5 ⍝ iota 5
			1 2 3 4 5

			⎕IO←0 ⍝ Set index origin ⎕IO to 0 (zero)

			⍳5 ⍝ iota 5 again but compare the results just below to just above
			0 1 2 3 4
			</pre>

	{{System Variables}}		{{System Variables}}
	{{Article footer}}		{{Article footer}}

Paul Robinson at 13:14, 13 March 2013

2013-03-13T13:14:55Z

← Older revision		Revision as of 09:14, 13 March 2013
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	{{System Variables}}		{{System Variables}}
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Paul Robinson at 18:14, 8 March 2013

2013-03-08T18:14:52Z

← Older revision		Revision as of 14:14, 8 March 2013
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	<h1><apl>{quad}IC</apl> - Index Origin</h1>		<h1><apl>{quad}IO</apl> - Index Origin</h1>
	{{BoxStart\|<apll>Z←⎕IO</apll>		{{BoxStart\|<apll>Z←⎕IO</apll>
	\| returns the current value of the Index Origin. }}		\| returns the current value of the Index Origin. }}

Paul Robinson: Created page with "

{quad}IC - Index Origin

{{BoxStart|Z←⎕IO | returns the current value of the Index Origin. }} {{BoxEnd|Z is an integer vector ..."

2013-03-08T18:14:32Z

Created page with "<h1><apl>{quad}IC</apl> - Index Origin</h1> {{BoxStart|<apll>Z←⎕IO</apll> | returns the current value of the Index Origin. }} {{BoxEnd|<apll>Z</apll> is an integer vector ..."

New page

<h1><apl>{quad}IC</apl> - Index Origin</h1>
{{BoxStart|<apll>Z←⎕IO</apll>
| returns the current value of the Index Origin. }}
{{BoxEnd|<apll>Z</apll> is an integer vector containing the current value of ⎕IO. This is the lowest value of an array subscript, and is either 1 or 0.}}<br/>

{| border="1" cellpadding="5" cellspacing="0" rules="none" summary=""
|| <apll>⎕IO←0</apll> || set the lowest subscript of an array to 0.
|-
| valign="top" |<apll>⎕IO←1</apll> || sets the lowest subscript for arrays to 1
|-
|}
<br />
⎕IO determines the lowest subscript for arrays. The default is 1, but can be changed to 0. If an attempt is made to set ⎕IO to a value higher than 1, it is set to 1. If an attempt is made to set ⎕IO to a value loweer than 0, it is set to 0. Setting ⎕IO to anything other than a number causes a DOMAIN ERROR.

{{System Variables}}