Class: Units::Measure
- Inherits:
-
Object
- Object
- Units::Measure
- Includes:
- ModalSupport::BracketConstructor, ModalSupport::StateEquivalent
- Defined in:
- lib/units/measure.rb
Instance Attribute Summary collapse
-
#magnitude ⇒ Object
readonly
Returns the value of attribute magnitude.
-
#units ⇒ Object
readonly
Returns the value of attribute units.
Class Method Summary collapse
Instance Method Summary collapse
- #*(other) ⇒ Object
- #**(n) ⇒ Object
- #+(other) ⇒ Object
- #-(other) ⇒ Object
- #-@ ⇒ Object
- #/(other) ⇒ Object
-
#abr ⇒ Object
more natural concise text representation If a block is passed, it is used to format the numeric magnitudes (Float numbers) (e.g., for localization) Units.units3*m/(2*s).abr{|v| v.to_s.tr(‘.’,‘,’) } # => “1,5 m/s”.
-
#base ⇒ Object
decompose to base units.
- #coerce(other) ⇒ Object
-
#describe ⇒ Object
more verbose description (not grammatically perfect).
-
#detailed_units(all_levels = false) ⇒ Object
decompose compound units.
-
#dimension ⇒ Object
dimension (quantity).
- #dimensionless? ⇒ Boolean
- #in(other, mode = :absolute) ⇒ Object
-
#initialize(*args) ⇒ Measure
constructor
A new instance of Measure.
- #inspect ⇒ Object
- #inverse ⇒ Object
-
#magnitude? ⇒ Boolean
less strict dimensionless condition (e.g. an angle is not a pure magnitude in this sense).
- #si_units ⇒ Object
- #to(units, mode = :absolute) ⇒ Object
-
#to_s ⇒ Object
represent in text using Ruby notation.
- #to_si ⇒ Object
-
#u ⇒ Object
dimension? unit? only_units? strip_units? units_measure?.
Constructor Details
#initialize(*args) ⇒ Measure
Returns a new instance of Measure.
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# File 'lib/units/measure.rb', line 7 def initialize(*args) if args.size==0 mag = 1.0 units = {} elsif args.size==1 case args.first when Numeric mag = args.first units = {} else mag = 1.0 units = args.first end elsif args.size==2 mag, units = args else raise ArgumentError, "wrong number of arguments (#{args.size} for 0, 1 or 2)" end @magnitude = mag # rename to value? case units when Symbol uinfo = Units.unit(units) if uinfo if uinfo.dim @units = {uinfo.dim=>[units,1]} else @magnitude *= uinfo.factor @units = {} end else raise ArgumentError,"Invalid symbol for Measure definition: #{units.inspect} " end when Measure @magnitude *= units.magnitude @units = units.units else @units = units end end |
Instance Attribute Details
#magnitude ⇒ Object (readonly)
Returns the value of attribute magnitude.
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# File 'lib/units/measure.rb', line 51 def magnitude @magnitude end |
#units ⇒ Object (readonly)
Returns the value of attribute units.
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# File 'lib/units/measure.rb', line 51 def units @units end |
Class Method Details
.combine(units, dim, unit, mult) ⇒ Object
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# File 'lib/units/measure.rb', line 115 def self.combine(units, dim, unit, mult) factor = 1 if units[dim] u,m = units[dim] if u!=unit factor *= Units.conversion_factor(unit, u)**mult end units[dim] = [u, m+mult] else units[dim] = [unit, mult] end factor end |
Instance Method Details
#*(other) ⇒ Object
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# File 'lib/units/measure.rb', line 138 def *(other) other = Units.units(other) if other.kind_of?(String) case other when Numeric mag = self.magnitude*other units = self.units else mag = self.magnitude*other.magnitude units = {} (self.units.keys | other.units.keys).each do |dim| other_u = other.units[dim] || [nil,0] this_u = self.units[dim] || [other_u.first,0] # mag *= Units.conversion_factor(this_u.first, other_u.first) if other_u.first mult = this_u.last+other_u.last mag *= Units.conversion_factor(other_u.first, this_u.first)**(other_u.last) if other_u.first units[dim] = [this_u.first, mult] end end units.reject!{|dim,(u,m)| m==0} Measure.new(mag, units) end |
#**(n) ⇒ Object
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# File 'lib/units/measure.rb', line 170 def **(n) raise ArgumentError,"Only integer powers are allowed for magnitudes" unless n.kind_of?(Integer) units = @units.dup units.each_pair do |dim, (u, m)| units[dim] = [u, m*n] end Measure.new @magnitude, units end |
#+(other) ⇒ Object
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# File 'lib/units/measure.rb', line 160 def +(other) other = Units.units(other) if other.kind_of?(String) Measure.new self.magnitude+other.to(self.units).magnitude, self.units end |
#-(other) ⇒ Object
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# File 'lib/units/measure.rb', line 165 def -(other) other = Units.units(other) if other.kind_of?(String) self + (-other) end |
#-@ ⇒ Object
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# File 'lib/units/measure.rb', line 188 def -@ Measure.new(-@magnitude, units) end |
#/(other) ⇒ Object
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# File 'lib/units/measure.rb', line 129 def /(other) other = Units.units(other) if other.kind_of?(String) self * (other.kind_of?(Numeric) ? 1.0/other : other.inverse) end |
#abr ⇒ Object
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# File 'lib/units/measure.rb', line 70 def abr txt = self.to_s.gsub('**','^').tr('*',' ') if block_given? txt.gsub!(/[+-]?((\d+_?)*\d+(\.(\d+_?)*\d+)?|\.(\d+_?)*\d+)([eE][+-]?(\d+_?)*\d+)?/) do v = $&.to_f yield v end end txt end |
#base ⇒ Object
decompose to base units
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# File 'lib/units/measure.rb', line 111 def base detailed_units true end |
#coerce(other) ⇒ Object
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# File 'lib/units/measure.rb', line 240 def coerce(other) # other = Units.units(other) if other.kind_of?(String) [Measure[other], self] end |
#describe ⇒ Object
more verbose description (not grammatically perfect)
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# File 'lib/units/measure.rb', line 61 def describe return @magnitude.to_s if magnitude? u_descr = Units.units_descr(@units, true) "#{@magnitude} #{u_descr}" end |
#detailed_units(all_levels = false) ⇒ Object
decompose compound units
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# File 'lib/units/measure.rb', line 82 def detailed_units(all_levels = false) mag = @magnitude prev_units = self.units units = {} loop do compound = false prev_units.each_pair do |dim, (unit,mul)| ud = Units.unit(unit) if ud.decomposition compound = true mag *= ud.decomposition.magnitude ud.decomposition.units.each_pair do |d, (u,m)| mag *= self.class.combine(units, d, u, m*mul) end else mag *= self.class.combine(units, dim, unit, mul) end end if all_levels && compound prev_units = units units = {} else break end end Measure.new mag, units end |
#dimension ⇒ Object
dimension (quantity)
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# File 'lib/units/measure.rb', line 250 def dimension q = nil u = self.base.si_units SI_UNITS.each_pair do |dim, unit| unit = Measure.new(1.0, unit) unless unit.kind_of?(Measure) if unit.base.si_units == u q = dim break end end q end |
#dimensionless? ⇒ Boolean
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# File 'lib/units/measure.rb', line 263 def dimensionless? base.units.reject{|d,(u,m)| m==0}.empty? end |
#in(other, mode = :absolute) ⇒ Object
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# File 'lib/units/measure.rb', line 192 def in(other, mode=:absolute) other = Units.units(other) if other.kind_of?(String) other = Measure.new(1.0, other) unless other.kind_of?(Measure) other = other.base this = self.base dims = this.units.keys | other.units.keys mag = this.magnitude/other.magnitude dims.each do |dim| if !this.units[dim] || !other.units[dim] || (this.units[dim].last != other.units[dim].last) raise "Inconsistent units #{Units.units_descr(this.units)} #{Units.units_descr(other.units)}" end this_u, mult = this.units[dim] other_u = other.units[dim].first mag *= Units.conversion_factor(this_u, other_u)**mult end if mode!=:relative && dims.size==1 && this.units[dims.first].last==1 # consider "level" conversion for biased units (otherwise consider interval or difference values) mag += Units.conversion_bias(this.units[dims.first].first, other.units[dims.first].first) end mag end |
#inspect ⇒ Object
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# File 'lib/units/measure.rb', line 134 def inspect "Units::Measure[#{@magnitude.inspect}, #{@units.inspect}]" end |
#inverse ⇒ Object
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# File 'lib/units/measure.rb', line 179 def inverse #Measure.new(1.0/@magnitude, @units.map_hash{|unit,mult| [unit, -mult]}) units = {} @units.each_pair do |dim, (unit, mult)| units[dim] = [unit, -mult] end Measure.new(1.0/@magnitude, units) end |
#magnitude? ⇒ Boolean
less strict dimensionless condition (e.g. an angle is not a pure magnitude in this sense)
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# File 'lib/units/measure.rb', line 268 def magnitude? self.units.reject{|d,(u,m)| m==0}.empty? end |
#si_units ⇒ Object
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# File 'lib/units/measure.rb', line 221 def si_units units = {} @units.each_pair do |dim, (unit, mult)| si_unit = SI_UNITS[dim] if si_unit.kind_of?(Measure) si_unit.units.each_pair do |d, (u,m)| self.class.combine(units, d, u, m*mult) end else self.class.combine(units, dim, si_unit, mult) end end units end |
#to(units, mode = :absolute) ⇒ Object
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# File 'lib/units/measure.rb', line 215 def to(units, mode=:absolute) units = Units.units(units) if units.kind_of?(String) units = units.u if units.kind_of?(Measure) Measure.new self.in(units, mode), units end |
#to_s ⇒ Object
represent in text using Ruby notation
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# File 'lib/units/measure.rb', line 54 def to_s return @magnitude.to_s if magnitude? u_descr = Units.units_descr(@units) "#{@magnitude}*#{u_descr}" end |
#to_si ⇒ Object
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# File 'lib/units/measure.rb', line 236 def to_si to(si_units) end |