Difference between revisions of "System Variable FPC"

From NARS2000
Jump to: navigation, search
Line 16: Line 16:
  
 
<p>
 
<p>
The approximate number of digits of precision for a given value of ⎕FPC is about 10⍟2*⎕FPC. The value of ⎕FPC for a given required precision is about ⌈2⍟10*digits.
+
The approximate number of digits of precision for a given value of <apll>⎕FPC</apll> is about <apll>10⍟2*⎕FPC</apll>. The value of <apll>⎕FPC</apll> for a given required precision is about <apll>⌈2⍟10*digits</apll>.
 
</p>
 
</p>
  

Revision as of 02:58, 26 October 2018

⎕FPC - Floating Point Control

Z←⎕FPC returns the current value of the Floating Point Control precision.
Z is an integer scalar that represents the current value of the number of bits of precision used for Multiple-Precision Floating Point numbers.


⎕FPC←R sets the value of the Floating Point Control precision to R.
⎕FPC←⍬ sets the value of the Floating Point Control precision to its system default state.


The approximate number of digits of precision for a given value of ⎕FPC is about 10⍟2*⎕FPC. The value of ⎕FPC for a given required precision is about ⌈2⍟10*digits.

The minimum value for ⎕FPC is 1; the maximum value is the largest positive 32-bit integer 2147483647.

The system default value is 128.


For example, (note: these numbers are normally one long string of digits; they are broken here, with the break shown by (continued) for your convenience in reading)

      ⎕PP←240 
      ⎕FPC←64  ⋄ *1x 
2.7182818284590452354 
      ⎕FPC←128 ⋄ *1x 
2.71828182845904523536028747135266249776 
      ⎕FPC←256 ⋄ *1x 
2.71828182845904523536028747135266249775724709369995957496696762 (Continued) 
772407663035355
      ⎕FPC←512 ⋄ *1x 
2.71828182845904523536028747135266249775724709369995957496696762 (Continued) 
7724076630353547594571382178525166427427466391932003059921817413 (Continued) 
5966290435729003342952605956 
      ⎕FPC←1024 ⋄ *1x 
2.71828182845904523536028747135266249775724709369995957496696762 (Continued) 
7724076630353547594571382178525166427427466391932003059921817413 (Continued) 
5966290435729003342952605956307381323286279434907632338298807531 (Continued) 
9525101901157383418793070215408914993488416750924

Whereas, according to Wolfram Alpha, the exact value to 230 digits is

2.71828182845904523536028747135266249775724709369995957496696762 (Continued)
7724076630353547594571382178525166427427466391932003059921817413 (Continued)
5966290435729003342952605956307381323286279434907632338298807531 (Continued)
9525101901157383418793070215408914993488...

See Also: Comparison Tolerance ⎕CT


System Variables (A value may be assigned to these except for ⎕DM)
ALX CT DM DT ELX FC FEATURE FPC IC IO
LR LX PP PR PW RL SA WSID
Niladic System Functions (a value cannot be assigned to these)
A AV EM ET LC NNAMES NNUMS SI SYSID SYSVER
T TC TCBEL TCBS TCESC TCFF TCHT TCLF TCNL TCNUL
TS WA
Monadic or dyadic system functions (a value cannot be assigned to these)
AT CR DC DFT DL DR EA EC ERROR ES
EX FMT FX MF NAPPEND NC NCREATE NERASE NINFO NL
NLOCK NREAD NRENAME NREPLACE NRESIZE NSIZE NTIE NUNTIE STOP TF
TRACE UCS VR
Note that quad functions and variables (except for the ⎕A family of functions) are case insensitive


See Also
System Commands System Variables and Functions Operators


Keyboard
A+S
Alt ¨ ¯ < > × ÷
Sh ~ ! @ # $ % ^ & * ( ) _ +
Key ` 1 2 3 4 5 6 7 8 9 0 - =
A+S
Alt ? π
Sh Q W E R T Y U I O P { } |
Key q w e r t y u i o p [ ] \
A+S §
Alt
Sh A S D F G H J K L : "
Key a s d f g h j k l ; '
A+S
Alt
Sh Z X C V B N M < > ?
Key z x c v b n m , . /
NARS 2000 Lang
Tool
Bar
+ - × ÷ * ! ? |
< = >
~ § π .. ,
/ \ ¨ .
_ ¯
Second Row i j k i j k l g p r v x

[[Category:Mouse Group {{{1}}}|{{{2}}}]]