math::bigrat.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

\&        my $h = Math::BigRat\->from_hex(\*(Aq0x10\*(Aq);
\&        my $b = Math::BigRat\->from_bin(\*(Aq0b10000000\*(Aq);
\&        my $o = Math::BigRat\->from_oct(\*(Aq020\*(Aq);
.Ve
.PP
Create a BigRat from an hexadecimal, binary or octal number
in string form.
.Sh "\fIlength()\fP"
.IX Subsection "length()"
.Vb 1
\&        $len = $x\->length();
.Ve
.PP
Return the length of \f(CW$x\fR in digitis for integer values.
.Sh "\fIdigit()\fP"
.IX Subsection "digit()"
.Vb 2
\&        print Math::BigRat\->new(\*(Aq123/1\*(Aq)\->digit(1);     # 1
\&        print Math::BigRat\->new(\*(Aq123/1\*(Aq)\->digit(\-1);    # 3
.Ve
.PP
Return the N'ths digit from X when X is an integer value.
.Sh "\fIbnorm()\fP"
.IX Subsection "bnorm()"
.Vb 1
\&        $x\->bnorm();
.Ve
.PP
Reduce the number to the shortest form. This routine is called
automatically whenever it is needed.
.Sh "\fIbfac()\fP"
.IX Subsection "bfac()"
.Vb 1
\&        $x\->bfac();
.Ve
.PP
Calculates the factorial of \f(CW$x\fR. For instance:
.PP
.Vb 2
\&        print Math::BigRat\->new(\*(Aq3/1\*(Aq)\->bfac(),"\en";    # 1*2*3
\&        print Math::BigRat\->new(\*(Aq5/1\*(Aq)\->bfac(),"\en";    # 1*2*3*4*5
.Ve
.PP
Works currently only for integers.
.Sh "\fIbround()\fP/\fIround()\fP/\fIbfround()\fP"
.IX Subsection "bround()/round()/bfround()"
Are not yet implemented.
.Sh "\fIbmod()\fP"
.IX Subsection "bmod()"
.Vb 4
\&        use Math::BigRat;
\&        my $x = Math::BigRat\->new(\*(Aq7/4\*(Aq);
\&        my $y = Math::BigRat\->new(\*(Aq4/3\*(Aq);
\&        print $x\->bmod($y);
.Ve
.PP
Set \f(CW$x\fR to the remainder of the division of \f(CW$x\fR by \f(CW$y\fR.
.Sh "\fIbneg()\fP"
.IX Subsection "bneg()"
.Vb 1
\&        $x\->bneg();
.Ve
.PP
Used to negate the object in-place.
.Sh "\fIis_one()\fP"
.IX Subsection "is_one()"
.Vb 1
\&        print "$x is 1\en" if $x\->is_one();
.Ve
.PP
Return true if \f(CW$x\fR is exactly one, otherwise false.
.Sh "\fIis_zero()\fP"
.IX Subsection "is_zero()"
.Vb 1
\&        print "$x is 0\en" if $x\->is_zero();
.Ve
.PP
Return true if \f(CW$x\fR is exactly zero, otherwise false.
.Sh "\fIis_pos()\fP/\fIis_positive()\fP"
.IX Subsection "is_pos()/is_positive()"
.Vb 1
\&        print "$x is >= 0\en" if $x\->is_positive();
.Ve
.PP
Return true if \f(CW$x\fR is positive (greater than or equal to zero), otherwise
false. Please note that '+inf' is also positive, while 'NaN' and '\-inf' aren't.
.PP
\&\f(CW\*(C`is_positive()\*(C'\fR is an alias for \f(CW\*(C`is_pos()\*(C'\fR.
.Sh "\fIis_neg()\fP/\fIis_negative()\fP"
.IX Subsection "is_neg()/is_negative()"
.Vb 1
\&        print "$x is < 0\en" if $x\->is_negative();
.Ve
.PP
Return true if \f(CW$x\fR is negative (smaller than zero), otherwise false. Please
note that '\-inf' is also negative, while 'NaN' and '+inf' aren't.
.PP
\&\f(CW\*(C`is_negative()\*(C'\fR is an alias for \f(CW\*(C`is_neg()\*(C'\fR.
.Sh "\fIis_int()\fP"
.IX Subsection "is_int()"
.Vb 1
\&        print "$x is an integer\en" if $x\->is_int();
.Ve
.PP
Return true if \f(CW$x\fR has a denominator of 1 (e.g. no fraction parts), otherwise
false. Please note that '\-inf', 'inf' and 'NaN' aren't integer.
.Sh "\fIis_odd()\fP"
.IX Subsection "is_odd()"
.Vb 1
\&        print "$x is odd\en" if $x\->is_odd();
.Ve
.PP
Return true if \f(CW$x\fR is odd, otherwise false.
.Sh "\fIis_even()\fP"
.IX Subsection "is_even()"
.Vb 1
\&        print "$x is even\en" if $x\->is_even();
.Ve
.PP
Return true if \f(CW$x\fR is even, otherwise false.
.Sh "\fIbceil()\fP"
.IX Subsection "bceil()"
.Vb 1
\&        $x\->bceil();
.Ve
.PP
Set \f(CW$x\fR to the next bigger integer value (e.g. truncate the number to integer
and then increment it by one).
.Sh "\fIbfloor()\fP"
.IX Subsection "bfloor()"
.Vb 1
\&        $x\->bfloor();
.Ve
.PP
Truncate \f(CW$x\fR to an integer value.
.Sh "\fIbsqrt()\fP"
.IX Subsection "bsqrt()"
.Vb 1
\&        $x\->bsqrt();
.Ve
.PP
Calculate the square root of \f(CW$x\fR.
.Sh "\fIbroot()\fP"
.IX Subsection "broot()"
.Vb 1
\&        $x\->broot($n);
.Ve
.PP
Calculate the N'th root of \f(CW$x\fR.
.Sh "\fIbadd()\fP/\fIbmul()\fP/\fIbsub()\fP/\fIbdiv()\fP/\fIbdec()\fP/\fIbinc()\fP"
.IX Subsection "badd()/bmul()/bsub()/bdiv()/bdec()/binc()"
Please see the documentation in Math::BigInt.
.Sh "\fIcopy()\fP"
.IX Subsection "copy()"
.Vb 1
\&        my $z = $x\->copy();
.Ve
.PP
Makes a deep copy of the object.
.PP
Please see the documentation in Math::BigInt for further details.
.Sh "\fIbstr()\fP/\fIbsstr()\fP"
.IX Subsection "bstr()/bsstr()"
.Vb 3
\&        my $x = Math::BigInt\->new(\*(Aq8/4\*(Aq);
\&        print $x\->bstr(),"\en";                  # prints 1/2
\&        print $x\->bsstr(),"\en";                 # prints 1/2
.Ve
.PP
Return a string representating this object.
.Sh "\fIbacmp()\fP/\fIbcmp()\fP"
.IX Subsection "bacmp()/bcmp()"
Used to compare numbers.
.PP
Please see the documentation in Math::BigInt for further details.
.Sh "\fIblsft()\fP/\fIbrsft()\fP"
.IX Subsection "blsft()/brsft()"
Used to shift numbers left/right.
.PP
Please see the documentation in Math::BigInt for further details.
.Sh "\fIbpow()\fP"
.IX Subsection "bpow()"
.Vb 1
\&        $x\->bpow($y);
.Ve
.PP
Compute \f(CW$x\fR ** \f(CW$y\fR.
.PP
Please see the documentation in Math::BigInt for further details.
.Sh "\fIbexp()\fP"
.IX Subsection "bexp()"
.Vb 1
\&        $x\->bexp($accuracy);            # calculate e ** X
.Ve
.PP
Calculates two integers A and B so that A/B is equal to \f(CW\*(C`e ** $x\*(C'\fR, where \f(CW\*(C`e\*(C'\fR is
Euler's number.
.PP
This method was added in v0.20 of Math::BigRat (May 2007).
.PP
See also \fIblog()\fR.
.Sh "\fIbnok()\fP"
.IX Subsection "bnok()"
.Vb 1
\&        $x\->bnok($y);              # x over y (binomial coefficient n over k)
.Ve
.PP
Calculates the binomial coefficient n over k, also called the \*(L"choose\*(R"
function. The result is equivalent to:
.PP
.Vb 3
\&        ( n )      n!
\&        | \- |  = \-\-\-\-\-\-\-
\&        ( k )    k!(n\-k)!
.Ve
.PP
This method was added in v0.20 of Math::BigRat (May 2007).
.Sh "\fIconfig()\fP"
.IX Subsection "config()"
.Vb 1
\&        use Data::Dumper;
\&
\&        print Dumper ( Math::BigRat\->config() );
\&        print Math::BigRat\->config()\->{lib},"\en";
.Ve
.PP
Returns a hash containing the configuration, e.g. the version number, lib
loaded etc. The following hash keys are currently filled in with the
appropriate information.
.PP
.Vb 10
\&        key             RO/RW   Description
\&                                Example
\&        ============================================================
\&        lib             RO      Name of the Math library
\&                                Math::BigInt::Calc
\&        lib_version     RO      Version of \*(Aqlib\*(Aq
\&                                0.30
\&        class           RO      The class of config you just called
\&                                Math::BigRat
\&        version         RO      version number of the class you used
\&                                0.10
\&        upgrade         RW      To which class numbers are upgraded
\&                                undef
\&        downgrade       RW      To which class numbers are downgraded
\&                                undef
\&        precision       RW      Global precision
\&                                undef
\&        accuracy        RW      Global accuracy
\&                                undef
\&        round_mode      RW      Global round mode
\&                                even
\&        div_scale       RW      Fallback accuracy for div
\&                                40
\&        trap_nan        RW      Trap creation of NaN (undef = no)
\&                                undef
\&        trap_inf        RW      Trap creation of +inf/\-inf (undef = no)
\&                                undef
.Ve
.PP
By passing a reference to a hash you may set the configuration values. This
works only for values that a marked with a \f(CW\*(C`RW\*(C'\fR above, anything else is
read-only.
.SH "BUGS"
.IX Header "BUGS"
Some things are not yet implemented, or only implemented half-way:
.IP "inf handling (partial)" 2
.IX Item "inf handling (partial)"
.PD 0
.IP "NaN handling (partial)" 2
.IX Item "NaN handling (partial)"
.IP "rounding (not implemented except for bceil/bfloor)" 2
.IX Item "rounding (not implemented except for bceil/bfloor)"
.ie n .IP "$x\fR ** \f(CW$y\fR where \f(CW$y is not an integer" 2
.el .IP "\f(CW$x\fR ** \f(CW$y\fR where \f(CW$y\fR is not an integer" 2
.IX Item "$x ** $y where $y is not an integer"
.IP "\fIbmod()\fR, \fIblog()\fR, \fIbmodinv()\fR and \fIbmodpow()\fR (partial)" 2
.IX Item "bmod(), blog(), bmodinv() and bmodpow() (partial)"
.PD
.SH "LICENSE"
.IX Header "LICENSE"
This program is free software; you may redistribute it and/or modify it under
the same terms as Perl itself.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Math::BigFloat and Math::Big as well as Math::BigInt::BitVect,
Math::BigInt::Pari and  Math::BigInt::GMP.
.PP
See <http://search.cpan.org/search?dist=bignum> for a way to use
Math::BigRat.
.PP
The package at <http://search.cpan.org/search?dist=Math%3A%3ABigRat>
may contain more documentation and examples as well as testcases.
.SH "AUTHORS"
.IX Header "AUTHORS"
(C) by Tels <http://bloodgate.com/> 2001 \- 2007.