Class: Nio::NeutralNum

Inherits:
Object
  • Object
show all
Includes:
StateEquivalent
Defined in:
lib/nio/fmt.rb,
lib/nio/fmt.rb

Overview

positional notation, unformatted numeric literal: used as intermediate form

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from StateEquivalent

#==, #===, #eql?, #hash

Constructor Details

#initialize(s = '', d = '', p = nil, r = nil, dgs = DigitsDef.base(10), inexact = false, round = :inf) ⇒ NeutralNum

Returns a new instance of NeutralNum.



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# File 'lib/nio/fmt.rb', line 26

def initialize(s='',d='',p=nil,r=nil,dgs=DigitsDef.base(10), inexact=false, round=:inf)
  set s,d,p,r,dgs,dgs, inexact, round
end

Instance Attribute Details

#dec_pos ⇒ Object

Returns the value of attribute dec_pos.



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# File 'lib/nio/fmt.rb', line 29

def dec_pos
  @dec_pos
end

#digits ⇒ Object

Returns the value of attribute digits.



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# File 'lib/nio/fmt.rb', line 29

def digits
  @digits
end

#inexact ⇒ Object

Returns the value of attribute inexact.



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# File 'lib/nio/fmt.rb', line 29

def inexact
  @inexact
end

#rep_pos ⇒ Object

Returns the value of attribute rep_pos.



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# File 'lib/nio/fmt.rb', line 29

def rep_pos
  @rep_pos
end

#rounding ⇒ Object

Returns the value of attribute rounding.



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# File 'lib/nio/fmt.rb', line 29

def rounding
  @rounding
end

#sign ⇒ Object

Returns the value of attribute sign.



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# File 'lib/nio/fmt.rb', line 29

def sign
  @sign
end

#special ⇒ Object

Returns the value of attribute special.



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# File 'lib/nio/fmt.rb', line 29

def special
  @special
end

Instance Method Details

#base ⇒ Object 



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# File 'lib/nio/fmt.rb', line 53

def base
  @base
end

#base=(b) ⇒ Object 



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# File 'lib/nio/fmt.rb', line 63

def base=(b)
  @dgs = DigitsDef.base(b)
  @base=@dgs.radix
end

#base_digits ⇒ Object 



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# File 'lib/nio/fmt.rb', line 56

def base_digits
  @dgs
end

#base_digits=(dd) ⇒ Object 



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# File 'lib/nio/fmt.rb', line 59

def base_digits=(dd)
  @dgs = dd
  @base = @dgs.radix
end

#dup ⇒ Object 



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# File 'lib/nio/fmt.rb', line 78

def dup
  n = NeutralNum.new
  if special?
    n.set_special @special.dup, @sign.dup
  else
    #n.set @sign.dup, @digits.dup, @dec_pos.dup, @rep_pos.dup, @dgs.dup
    # in Ruby 1.6.8 Float,BigNum,Fixnum doesn't respond to dup
    n.set @sign.dup, @digits.dup, @dec_pos, @rep_pos, @dgs.dup, @inexact, @rounding
  end
  return n 
end

#inexact? ⇒ Boolean

check for special numbers (which have only special and sign attributes)

Returns:

  • (Boolean) 


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# File 'lib/nio/fmt.rb', line 74

def inexact?
  @inexact
end

#round(n, mode = :fix, dir = nil) ⇒ Object 



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# File 'lib/nio/fmt.rb', line 201

def round(n, mode=:fix, dir=nil)
  dir ||= rounding
  nn = dup
  nn.round!(n,mode,dir)
  return nn
end

#round!(n, mode = :fix, dir = nil) ⇒ Object 



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# File 'lib/nio/fmt.rb', line 108

def round!(n, mode=:fix, dir=nil)
  dir ||= rounding
  trimLeadZeros
  if n==:exact
    return unless @inexact
    n = @digits.size
  end
  
  n += @dec_pos if mode==:fix
  n = [n,@digits.size].min if @inexact

  adj = 0
  dv = :tie
  if @inexact && n==@digits.size
    dv = @inexact==:roundup ? :hi : :lo
  else
    v = dig_value(n)
    v2 = 2*v
    if v2 < @base # v<((@base+1)/2)
      dv = :lo
    elsif v2 > @base # v>(@base/2)
      dv = :hi
    else
     
     (n+1...@digits.length).each do |i|
       if dig_value(i)>0
         dv = :hi
         break
       end        
     end
      
      dv = :hi if dv==:tie && @rep_pos<=n                  
    end
  end
  
  if dv==:hi
    adj = +1
  elsif dv==:tie
    if dir==:inf # towards nearest +/-infinity
      adj = +1
    elsif dir==:even # to nearest even digit (IEEE unbiased rounding)
      adj = +1 if (dig_value(n-1)%2)!=0
    elsif dir==:zero # towards zero
      adj=0
  #  elsif dir==:odd 
  #    adj = +1 unless (dig_value(n-1)%2)!=0
    end
  end    
  
  if n>@digits.length
    (@digits.length...n).each do |i|
      @digits << dig_char(dig_value(i))
      @rep_pos += 1
    end
  end
  
  prefix = ''
  i = n-1
  while adj!=0
    v = dig_value(i)
    v += adj
    adj = 0
    if v<0
      v += @base
      adj = -1
    elsif v>=@base
      v -= @base
      adj = +1
    end
    if i<0
      prefix = dig_char(v)+prefix 
    elsif i<@digits.length
      @digits[i] = dig_char(v)
    end
    i += -1
  end 
  
  if n<0
    @digits = ""  
  else
    @digits = @digits[0...n]  
  end
  @rep_pos = @digits.length

  if prefix!=''
    @digits = prefix + @digits
    @dec_pos += prefix.length
    @rep_pos += prefix.length
  end
  
  
end

#set(s, d, p = nil, r = nil, dgs = DigitsDef.base(10), inexact = false, rounding = :inf, normalize = true) ⇒ Object

set number



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# File 'lib/nio/fmt.rb', line 33

def set(s,d,p=nil,r=nil,dgs=DigitsDef.base(10),inexact=false,rounding=:inf,normalize=true)
  @sign = s # sign: '+','-',''
  @digits = d # digits string
  @dec_pos = p==nil ? d.length : p # position of decimal point: 0=before first digit...
  @rep_pos = r==nil ? d.length : r # first repeated digit (0=first digit...)
  @dgs = dgs
  @base = @dgs.radix
  @inexact = inexact
  @special = nil
  @rounding = rounding
  trimZeros unless inexact  
  self
end

#set_special(s, sgn = '') ⇒ Object

set infinite (:inf) and invalid (:nan) numbers



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# File 'lib/nio/fmt.rb', line 47

def set_special(s,sgn='') # :inf, :nan
  @special = s
  @sign = sgn
  self
end

#special? ⇒ Boolean

check for special numbers (which have only special and sign attributes)

Returns:

  • (Boolean) 


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# File 'lib/nio/fmt.rb', line 69

def special?
  special != nil
end

#to_RepDec ⇒ Object 



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# File 'lib/nio/fmt.rb', line 283

def to_RepDec
  n = RepDec.new(@base)
  if special?
    
    case special
      when :nan
        n.ip = :indeterminate
      when :inf
        if sign=='-'
          n.ip = :posinfinity
        else
          n.ip  :neginfinity
        end
      else
        n = nil
    end
    
  else
    if dec_pos<=0
      n.ip = 0
      n.d =  text_to_digits(dig_char(0)*(-dec_pos) + digits)
    elsif dec_pos >= digits.length
      n.ip = digits.to_i(@base)        
      if rep_pos<dec_pos          
        i=0
        (dec_pos-digits.length).times do
          n.ip *= @base
          n.ip += @dgs.digit_value(digits[rep_pos+i]) if rep_pos+i<digits.length
          i += 1
          i=0 if i>=digits.length-rep_pos
        end
        n.d = []
        while i<digits.length-rep_pos
          n.d << @dgs.digit_value(digits[rep_pos+i])
          i += 1
        end
        new_rep_pos = n.d.size + dec_pos
        n.d += text_to_digits(digits[rep_pos..-1])
        self.rep_pos = new_rep_pos
      else
        n.ip *= @base**(dec_pos-digits.length)
        n.d = []
      end
    else
      n.ip = digits[0...dec_pos].to_i(@base)
      n.d = text_to_digits(digits[dec_pos..-1])
      if rep_pos<dec_pos 
        new_rep_pos = n.d.size + dec_pos
        n.d += text_to_digits(digits[rep_pos..-1])
        self.rep_pos = new_rep_pos
        puts "--rep_pos=#{rep_pos}"
      end        
    end
    n.sign = -1 if sign=='-'
    n.rep_i = rep_pos - dec_pos     
  end
  n.normalize!(!inexact) # keep trailing zeros for inexact numbers
  return n
end

#trimLeadZeros ⇒ Object 



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# File 'lib/nio/fmt.rb', line 226

def trimLeadZeros()
  i = 0
  while i<@digits.length && dig_value(i)==0
    i += 1
  end
  @digits = @digits[i...@digits.length]
  @dec_pos -= i
  @rep_pos -= i
  
  if @digits==''
    @digits = dig_char(0) # '0'
    @rep_pos = 1
    @dec_pos = 1
  end
  
end

#trimTrailZeros ⇒ Object 



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# File 'lib/nio/fmt.rb', line 208

def trimTrailZeros()    
  i = @digits.length
  while i>0 && dig_value(i-1)==0
    i -= 1    
  end
  if @rep_pos>=i
    @digits = @digits[0...i]
    @rep_pos = i
  end
  
  if @digits==''
    @digits = dig_char(0) # '0'
    @rep_pos = 1
    @dec_pos = 1
  end
  
end

#trimZeros ⇒ Object 



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# File 'lib/nio/fmt.rb', line 243

def trimZeros()    
  trimLeadZeros
  trimTrailZeros
end

#zero? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nio/fmt.rb', line 90

def zero?
  z = false
  if !special
    if digits==''
      z = true
    else
      z = true
      for i in (0...@digits.length)
        if dig_value(i)!=0
          z = false
          break
        end
      end
    end
  end
  z
end