System Variable PP - Revision history

WikiSysop at 17:00, 16 April 2018

2018-04-16T17:00:27Z

← Older revision		Revision as of 13:00, 16 April 2018
Line 1:		Line 1:
	<h1>~~{quad}PP~~ - Print Precision</h1>		<h1><aplxx>⎕PP</aplxx> - Print Precision</h1>
	{{BoxStart\|⎕PP		{{BoxStart\|⎕PP
	\| Print Precision}}		\| Print Precision}}
	{{BoxEnd\|⎕PP←'<i>VALUE</i>'}}		{{BoxEnd\|⎕PP←'<i>VALUE</i>'}}

	System Variable ~~'''~~⎕PP~~''' or '''Quad PP'''~~ refers to Print Precision.		System Variable <apll>⎕PP</apll> refers to Print Precision.
	In ~~NARS~~, the default Print Precision is:		In NARS2000, the default Print Precision is:
	<pre>
			<apll><pre>
	⎕PP		⎕PP
	10		10
Line 28:		Line 29:
	X		X
	0.3333 ⍝ but X now only has 4 significant digits in it, as a result of ⎕PP reduction, formatting and re-execution into a number.		0.3333 ⍝ but X now only has 4 significant digits in it, as a result of ⎕PP reduction, formatting and re-execution into a number.
	</pre>		</pre></apll>
	Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-~~bit systems~~, higher print precision values ~~are available~~. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that ~~'''~~print precision does NOT ~~normally~~ affect stored/digitized numbers, unless''' the numbers were first formatted/printed, then re-executed into digital floating point numbers as the above example shows.
			Although 10 significant digits represent the print precision or displayed precision, actual computer stored formats are quite different. Historically or customarily, <apll>⎕PP</apll> is normally assigned a value of between 1 and 16, although with [[Rational_and_VFP_Numbers\|Multiple-precision Floating Point numbers]], higher print precision values may be needed. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean <apll>⎕PP</apll> should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that print precision does NOT affect stored/digitized numbers, '''unless''' the numbers were first formatted/printed, then re-executed into digital floating point numbers as the above example shows.

			See also '''[[System_Function_DR\|System Function ⎕DR]]'''.

	~~See also '''[[System_Function_DR\|System Function ⎕DR]]'''.<br>~~
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Robert Wallick: expanded example

2015-08-22T01:54:00Z

expanded example

← Older revision		Revision as of 21:54, 21 August 2015
Line 15:		Line 15:
	⍴⍕1÷3		⍴⍕1÷3
	12 ⍝ 10 significant digits after the decimal point, plus 0 and decimal point itself = 12 chars (shape)		12 ⍝ 10 significant digits after the decimal point, plus 0 and decimal point itself = 12 chars (shape)

			X←1÷3
			X
			0.3333333333
			⎕PP←4 ⍝ print precision changed to 4 digits
			X
			0.3333
			X←⍎⍕X ⍝ X is now formatted(printed) and re-executed into a number (for demonstration purposes only, AVOID in practice!!!)
			X
			0.3333
			⎕PP←10 ⍝ print precision is restored to 10 digits
			X
			0.3333 ⍝ but X now only has 4 significant digits in it, as a result of ⎕PP reduction, formatting and re-execution into a number.
	</pre>		</pre>
	Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-bit systems, higher print precision values are available. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that print precision does NOT normally affect stored/digitized numbers, unless the numbers were first formatted/printed, then re-executed into digital floating point numbers.		Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-bit systems, higher print precision values are available. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that '''print precision does NOT normally affect stored/digitized numbers, unless''' the numbers were first formatted/printed, then re-executed into digital floating point numbers as the above example shows.

	See also '''[[System_Function_DR\|System Function ⎕DR]]'''.<br>		See also '''[[System_Function_DR\|System Function ⎕DR]]'''.<br>

Robert Wallick: added example

2015-08-22T01:40:42Z

added example

← Older revision		Revision as of 21:40, 21 August 2015
Line 9:		Line 9:
	⎕PP		⎕PP
	10		10
			1÷3
			0.3333333333 ⍝ 10 significant digits after the decimal point are shown
			⍕1÷3
			0.3333333333 ⍝ 10 significant digits after the decimal point are shown, for formatted result
			⍴⍕1÷3
			12 ⍝ 10 significant digits after the decimal point, plus 0 and decimal point itself = 12 chars (shape)
	</pre>		</pre>
	Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-bit systems, higher print precision values are available. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that print precision does NOT normally affect stored/digitized numbers, unless the numbers were first formatted/printed, then re-executed into digital floating point numbers.		Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-bit systems, higher print precision values are available. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that print precision does NOT normally affect stored/digitized numbers, unless the numbers were first formatted/printed, then re-executed into digital floating point numbers.

Robert Wallick: wording, description

2015-08-22T01:32:52Z

wording, description

← Older revision		Revision as of 21:32, 21 August 2015
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	<h1>{quad}PP - ~~DEFINITION NEEDED~~</h1>		<h1>{quad}PP - Print Precision</h1>
	{{BoxStart\|⎕PP		{{BoxStart\|⎕PP
	\| ~~DEFINITION NEEDED~~}}		\| Print Precision}}
	{{BoxEnd\|⎕PP←'<i>VALUE</i>'}}		{{BoxEnd\|⎕PP←'<i>VALUE</i>'}}

	~~Description here~~ - ~~to do~~		System Variable '''⎕PP''' or '''Quad PP''' refers to Print Precision.
			In NARS, the default Print Precision is:
			<pre>
			⎕PP
			10
			</pre>
			Although 10 significant digits represent the print precision or displayed precision - actual computer stored formats are quite different. Historically or customarily, ⎕PP is normally assigned a value of between 1 and 16, although with 64-bit systems, higher print precision values are available. As an example, pollution is frequently cited in PPM's or parts per million or say 1 in 1,000,000 so 5-signficant digits in the data plus 7 digits within a million base might mean ⎕PP should be set as 5+7 = 12 significant digits, or greater for higher precision printed reports. Note that print precision does NOT normally affect stored/digitized numbers, unless the numbers were first formatted/printed, then re-executed into digital floating point numbers.

			See also '''[[System_Function_DR\|System Function ⎕DR]]'''.<br>
	{{System Variables}}		{{System Variables}}
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Paul Robinson: new stub

2014-11-26T10:18:43Z

new stub

New page

<h1>{quad}PP - DEFINITION NEEDED</h1>
{{BoxStart|⎕PP
| DEFINITION NEEDED}}
{{BoxEnd|⎕PP←'<i>VALUE</i>'}}

Description here - to do

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