Class: FixedPoint::Format

Inherits:
Object
  • Object
show all
Defined in:
lib/fixed_point/format.rb

Direct Known Subclasses

Fixdt

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(signed, int_bits, frac_bits) ⇒ Format

Returns a new instance of Format.



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# File 'lib/fixed_point/format.rb', line 14

def initialize(signed, int_bits, frac_bits)
  @signed    = signed
  @int_bits  = int_bits
  @frac_bits = frac_bits

  calculate_attributes(signed, int_bits, frac_bits)
end

Instance Attribute Details

#frac_bits ⇒ Object (readonly)

Returns the value of attribute frac_bits.



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# File 'lib/fixed_point/format.rb', line 5

def frac_bits
  @frac_bits
end

#int_bits ⇒ Object (readonly)

Returns the value of attribute int_bits.



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# File 'lib/fixed_point/format.rb', line 5

def int_bits
  @int_bits
end

#max_frac ⇒ Object (readonly)

Returns the value of attribute max_frac.



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# File 'lib/fixed_point/format.rb', line 11

def max_frac
  @max_frac
end

#max_int_signed ⇒ Object (readonly)

Returns the value of attribute max_int_signed.



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# File 'lib/fixed_point/format.rb', line 10

def max_int_signed
  @max_int_signed
end

#max_int_unsigned ⇒ Object (readonly)

Returns the value of attribute max_int_unsigned.



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# File 'lib/fixed_point/format.rb', line 10

def max_int_unsigned
  @max_int_unsigned
end

#max_signed ⇒ Object (readonly)

Returns the value of attribute max_signed.



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# File 'lib/fixed_point/format.rb', line 12

def max_signed
  @max_signed
end

#max_unsigned ⇒ Object (readonly)

Returns the value of attribute max_unsigned.



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# File 'lib/fixed_point/format.rb', line 12

def max_unsigned
  @max_unsigned
end

#max_value ⇒ Object (readonly)

Returns the value of attribute max_value.



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# File 'lib/fixed_point/format.rb', line 9

def max_value
  @max_value
end

#min_value ⇒ Object (readonly)

Returns the value of attribute min_value.



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# File 'lib/fixed_point/format.rb', line 9

def min_value
  @min_value
end

#resolution ⇒ Object (readonly)

Returns the value of attribute resolution.



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# File 'lib/fixed_point/format.rb', line 9

def resolution
  @resolution
end

#signed ⇒ Object (readonly)

Returns the value of attribute signed.



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# File 'lib/fixed_point/format.rb', line 5

def signed
  @signed
end

#width ⇒ Object (readonly)

Calculated attributes



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# File 'lib/fixed_point/format.rb', line 8

def width
  @width
end

Instance Method Details

#calculate_attributes(signed, int_bits, frac_bits) ⇒ Object

Format Should hold the maxim possible values not part of number (Value)



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# File 'lib/fixed_point/format.rb', line 28

def calculate_attributes(signed, int_bits, frac_bits)
  @width     = int_bits + frac_bits

  #Calculate Number ranges
  @resolution       = 2**(-@frac_bits)
  @max_frac         = 1 - 2**(-@frac_bits)
  @max_int_signed   = ( 2**(@int_bits - 1) - 1)
  @max_int_unsigned = ( 2**@int_bits       - 1)
  @max_signed       = @max_int_signed   + @max_frac
  @max_unsigned     = @max_int_unsigned + @max_frac

  @min_signed       = (-2**(@int_bits-1))
  @min_unsigned     = 0

  #Set Max/Min values
  if signed?
    @max_value = @max_signed
    @min_value = @min_signed 
  else 
    @max_value = @max_unsigned
    @min_value = @min_unsigned
  end

end

#signed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fixed_point/format.rb', line 22

def signed?
  (@signed == 1)
end