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Diffstat (limited to 'ext/bigdecimal/bigdecimal_en.html')
| -rw-r--r-- | ext/bigdecimal/bigdecimal_en.html | 89 |
1 files changed, 54 insertions, 35 deletions
diff --git a/ext/bigdecimal/bigdecimal_en.html b/ext/bigdecimal/bigdecimal_en.html index 04dd83a429..5344720adc 100644 --- a/ext/bigdecimal/bigdecimal_en.html +++ b/ext/bigdecimal/bigdecimal_en.html @@ -81,21 +81,29 @@ to create BigDecimal objects,the program would like:<BR> <CODE><PRE> require 'bigdecimal' a=BigDecimal::new("0.123456789123456789") - b=BigDecimal::new("123456.78912345678",40) + b=BigDecimal("123456.78912345678",40) c=a+b </PRE></CODE> <H3>List of methods</H3> -In the following explanations,n specifies the minimum number of resulting significant digits, -not exactly but slightly excess memories will be allocated to newly created object. In 32 bits integer system,every 4 digits(in decimal) are computed simultaneously. This means the number of significant digits in BigDecimal is always a multiple of 4. +<P> +Some more methods are available in Ruby code (not C code). +To use them,just require util.rb as: +<PRE><CODE> +require "bigdecimal/util.rb" +</CODE></PRE> +String to BigDecimal conversion, BigDecimal to String conversion +(in "nnnnnn.mmmm" form not in "0.xxxxxEn" form) etc are defined. +For details,see the util.rb code. <H4><U>Class methods</U></H4> <UL> <LI><B>new</B></LI><BLOCKQUOTE> "new" method creates a new BigDecimal object.<BR> -a=BigDecimal::new(s[,n])<BR> +a=BigDecimal::new(s[,n]) or<BR> +a=BigDecimal(s[,n]) or<BR> where:<BR> s: Initial value string.<BR> n: Maximum number of significant digits of a. n must be a Fixnum object. @@ -187,18 +195,6 @@ Base value used in the BigDecimal calculation. On 32 bits integer system,the value of BASE is 10000.<BR> b = BigDecimal::BASE<BR> </BLOCKQUOTE> - -<LI><B>E</B></LI><BLOCKQUOTE> -e = BigDecimal::E(n)<BR> -where e(=2.718281828....) is the base value of natural logarithm.<BR> -n specifies the length of significant digits of e. - -</BLOCKQUOTE> -<LI><B>PI</B></LI><BLOCKQUOTE> -e = BigDecimal::PI(n)<BR> -returns at least n digits of the ratio of the circumference of a circle to its diameter -(pi=3.14159265358979....) using J.Machin's formula.<BR> -</BLOCKQUOTE> </UL> <H4><U>Instance methods</U></H4> @@ -394,14 +390,15 @@ means a = 0.xxxxxxx*10**n. </BLOCKQUOTE> <LI><B>to_f</B></LI><BLOCKQUOTE> -same as dup method. -creates a new BigDecimal object having same value. +Creates a new Float object having (nearly) the same value. +Use split method if you want to convert by yourself. </BLOCKQUOTE> </BLOCKQUOTE> <LI><B>sign</B></LI><BLOCKQUOTE> -returns the 'attribute' of a. n = a.sign <BR> +returns positive value if a > 0,negative value if a < 0, +otherwise zero if a == 0.<BR> where the value of n means that a is:<BR> n = BigDecimal::SIGN_NaN(0) : a is NaN<BR> n = BigDecimal::SIGN_POSITIVE_ZERO(1) : a is +0<BR> @@ -455,28 +452,13 @@ where "0x112344" is the address, '0.314E1' is the value,4 is the number of the significant digits, and 12 is the maximum number of the significant digits the object can hold. - </BLOCKQUOTE> -<LI><B>dup</B></LI><BLOCKQUOTE> -creates a new BigDecimal object having same value. -</BLOCKQUOTE> <LI><B>sqrt</B></LI><BLOCKQUOTE> c = a.sqrt(n)<BR> computes square root value of a with significant digit number n at least.<BR> - -</BLOCKQUOTE> -<LI><B>sincos</B></LI><BLOCKQUOTE> -computes and returns sine and cosine value of a with significant digit number n at least.<BR> -sin,cos = a.sincos(n)<BR> -Computation may return bad results unless |a|<2*3.1415..... </BLOCKQUOTE> -<LI><B>exp</B></LI><BLOCKQUOTE> -c = a.exp(n)<BR> -computes the base of natural logarithm value(e=2.718281828....) powered by a -with significant digit number n at least.<BR> -</BLOCKQUOTE> <LI><B>**</B></LI><BLOCKQUOTE> c = a ** n<BR> returns the value of a powered by n. @@ -507,6 +489,41 @@ same as ==,used in case statement. <LI>></LI> <LI>>=</LI> </UL> + +<H4><U>Class methods(trial version)</U></H4> +Following class methods are in trial stage, and not usable in default. +Uncomment /* #define ENABLE_TRIAL_METHOD */ in bigdecimal.c, compile and install +again if you want to use. +<UL> +<LI><B>E</B></LI><BLOCKQUOTE> +e = BigDecimal::E(n)<BR> +where e(=2.718281828....) is the base value of natural logarithm.<BR> +n specifies the length of significant digits of e. + +</BLOCKQUOTE> +<LI><B>PI</B></LI><BLOCKQUOTE> +e = BigDecimal::PI(n)<BR> +returns at least n digits of the ratio of the circumference of a circle to its diameter +(pi=3.14159265358979....) using J.Machin's formula.<BR> +</BLOCKQUOTE> +</UL> + +<H4><U>Instance methods(trial version)</U></H4> +Following instance methods are in trial stage, and not usable in default. +Uncomment /* #define ENABLE_TRIAL_METHOD */ in bigdecimal.c, compile and install +again if you want to use. +<UL> +<LI><B>sincos</B></LI><BLOCKQUOTE> +computes and returns sine and cosine value of a with significant digit number n at least.<BR> +sin,cos = a.sincos(n)<BR> +Computation may return bad results unless |a|<2*3.1415..... +</BLOCKQUOTE> +<LI><B>exp</B></LI><BLOCKQUOTE> +c = a.exp(n)<BR> +computes the base of natural logarithm value(e=2.718281828....) powered by a +with significant digit number n at least.<BR> +</BLOCKQUOTE> +</UL> <HR> <H3>About 'coerce'</H3> @@ -521,7 +538,9 @@ same as ==,used in case statement. BigDecimal object and the operation is performed,otherwise an error occures.</DD> </DL> -Attention must be paid when a String is to be translated to BigDecimal. +String is not translated to BigDecimal in default. +Uncomment /* #define ENABLE_NUMERIC_STRING */ in bigdecimal.c, compile and install +again if you want to enable string to BigDecimal conversion. Translation stops without error at the character representing non digit. For instance,"10XX" is translated to 10,"XXXX" is translated to 0.<BR> String representing zero or infinity such as "Infinity","+Infinity","-Infinity",and "NaN" can also be translated to BigDecimal unless false is specified by mode method.<BR> |