# ⎕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 integer 1073741695 ←→ ¯129+2*30 ←→ 16b3FFFFF7F.

The system default value is 128.

For example:

```        ⎕PP←240
⎕FPC←64   ⋄ *1x
2.7182818284590452354
⎕FPC←128  ⋄ *1x
2.71828182845904523536028747135266249776
⎕FPC←256  ⋄ *1x
2.71828182845904523536028747135266249775724709369995957496696762
➥      772407663035355
⎕FPC←512  ⋄ *1x
2.71828182845904523536028747135266249775724709369995957496696762
➥      7724076630353547594571382178525166427427466391932003059921
➥      8174135966290435729003342952605956
⎕FPC←1024 ⋄ *1x
2.71828182845904523536028747135266249775724709369995957496696762
➥      7724076630353547594571382178525166427427466391932003059921
➥      8174135966290435729003342952605956307381323286279434907632
➥      3382988075319525101901157383418793070215408914993488416750
➥      924```

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

```  2.71828182845904523536028747135266249775724709369995957496696762
➥      7724076630353547594571382178525166427427466391932003059921
➥      8174135966290435729003342952605956307381323286279434907632
➥      3382988075319525101901157383418793070215408914993488...```

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 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 LangToolBar ← → + - × ÷ * ⍟ ⌹ ○ ! ? √ | ⌈ ⌊ ⊥ ⊤ ⊣ ⊢ = ≠ ≤ < > ≥ ≡ ≢ ∨ ∧ ⍱ ⍲ ↑ ↓ ⊂ ⊃ ⌷ ⍋ ⍒ ⍳ ∊ ⍸ ⍷ ∪ ∩ ⊆ ⊇ ~ § π .. , ⍪ ⍴ ⌽ ⊖ ⍉ / \ ⌿ ⍀ ⊙ ¨ ⍨ ⍤ ⍦ ⍥ . ∘ ⍠ ‼ ⌻ ⍞ ⎕ ⍎ ⍕ ⋄ ⍝ ∇ ∆ ⍙ _ ⍺ ⍵ ¯ ⍬ ∞ ∅ b e g p r v x