rsc3/doc-schelp/HelpSource/Classes/Float.scrbl

110 lines
2.2 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Float}
Floating point number@section{categories}
Math
@section{description}
A 64-bit double precision floating point number. Float inherits most of its behaviour from its superclass.
Note that despite its name, link::Classes/FloatArray:: only holds 32-bit (single precision) floats.
For a raw array of 64-bit floats, use link::Classes/DoubleArray::.
@section{ClassMethods}
@section{method}
from32Bits
@section{returns}
a new Float from a 32 bit word.
@section{method}
from64Bits
@section{returns}
a new Float from a 64 bit word.
@section{InstanceMethods}
@section{method}
do
iterates a link::Classes/Function:: from
@racketblock[0:: to ]
@racketblock[this-1::. See also: link::Classes/Integer#-do::, link::Classes/Collection#-do::
]
@section{argument}
function
The function to iterate.
@section{method}
reverseDo
iterates function from this-1 to 0
@section{argument}
function
The function to iterate.
@section{method}
coin
Perform a random test whose probability of success in a range from
zero to one is this and return the result.
@section{returns}
a link::Classes/Boolean::
@section{discussion}
@racketblock[
0.2.coin; // 20 % chance for true.
::
See also: link::Guides/Randomness::
]
@section{method}
isFloat
@section{returns}
@racketblock[true:: since this is a Float.
]
@section{method}
asFloat
@section{returns}
@racketblock[this:: since this is a Float.
]
@section{method}
as32Bits
@section{returns}
an Integer which is the bit pattern of this as a 32bit single precision float
@section{method}
high32Bits
@section{returns}
an Integer which is the bit pattern of high 32 bits of the 64 bit double precision floating point value
@section{method}
low32Bits
@section{returns}
an Integer which is the bit pattern of high 32 bits of the 64 bit double precision floating point value
@section{method}
asStringPrec
Returns a string representation of the number, with the desired precision (i.e. number of significant figures).
@section{discussion}
@racketblock[
// example:
pi
pi.asStringPrec(3)
pi.asStringPrec(6)
(pi * 0.0001).asStringPrec(3)
7.4.asStringPrec(5)
7.4.asStringPrec(50)
::
]