Class: Statsample::SEM::Model

Inherits:
Object
  • Object
show all
Includes:
Summarizable
Defined in:
lib/statsample/sem/model.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = Hash.new, &block) ⇒ Model

Returns a new instance of Model.

Raises:

  • (ArgumentError) 


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# File 'lib/statsample/sem/model.rb', line 19

def initialize(opts=Hash.new, &block)
  raise ArgumentError,"opts should be a Hash" if !opts.is_a? Hash
  default_opts={:name=>_("SEM Model")}
  @opts=default_opts.merge opts
  @paths=Hash.new
  @manifests=nil
  @latents=nil
  if block
    block.arity<1 ? self.instance_eval(&block) : block.call(self)
  end
end

Instance Attribute Details

#cases ⇒ Object

Number of cases



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# File 'lib/statsample/sem/model.rb', line 12

def cases
  @cases
end

#data_type ⇒ Object (readonly)

Type of data used. Could be :covariance, :correlation or :raw



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# File 'lib/statsample/sem/model.rb', line 6

def data_type
  @data_type
end

#ds ⇒ Object (readonly)

Raw data on a dataset



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# File 'lib/statsample/sem/model.rb', line 10

def ds
  @ds
end

#matrix ⇒ Object (readonly)

Covariance/correlation matrix



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# File 'lib/statsample/sem/model.rb', line 8

def matrix
  @matrix
end

#means ⇒ Object

Optional array of mean for use when data is matrix based



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# File 'lib/statsample/sem/model.rb', line 14

def means
  @means
end

#paths ⇒ Object (readonly)

Returns the value of attribute paths.



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# File 'lib/statsample/sem/model.rb', line 18

def paths
  @paths
end

#variables ⇒ Object

Name of variables



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# File 'lib/statsample/sem/model.rb', line 16

def variables
  @variables
end

Instance Method Details

#add_path(f1, f2, arrows, free, values, labels, i) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 68

def add_path(f1,f2,arrows,free,values,labels,i)
  arrow_s = (arrows==1) ? "to":"cov"
  raise "Path repeated : #{f1},#{f2}" if @paths.has_key? [[f1,f2].sort]
  label= (labels.nil? or !labels.respond_to?:[] or labels[i].nil?) ? "#{f1} #{arrow_s} #{f2}" : labels[i]
  
  free_v = (free.is_a? Array) ? free[i] : free 
  if values.is_a? Array
    value= values[i].nil? ? nil : values[i]
  elsif values.is_a? Numeric
    value=values
  end
    
  value = nil if free_v
  
  @paths[[f1,f2].sort]={ :from=>f1, :to=>f2, :arrow=>arrows, :label=>label, :free=>free_v, :value=>value}
end

#add_raw_path(f1, f2, arrows, label, free, value) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 65

def add_raw_path(f1,f2,arrows,label,free,value)
  @paths[[f1,f2].sort]={ :from=>f1, :to=>f2, :arrow=>arrows, :label=>label, :free=>free, :value=>value}
end

#complete? ⇒ Boolean

True if model have enough information to process it

Returns:

  • (Boolean) 


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# File 'lib/statsample/sem/model.rb', line 62

def complete?
  !@data_type.nil? and !@manifests.nil? and !@latents.nil? and @paths.size>0
end

#data_from_dataset(ds) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 218

def data_from_dataset(ds)
  @data_type=:raw
  @ds=ds
  @variables=@ds.fields
end

#data_from_matrix(matrix, opts = Hash.new) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 224

def data_from_matrix(matrix,opts=Hash.new)
  type = opts[:type]
  type||=(matrix.respond_to? :type) ? matrix.type : :covariance
  variable_names = opts[:variable_names]
  cases = opts[:cases]
  means = opts[:means]
  raise "You should set number of cases" if cases.nil?
  
  @data_type= (type==:covariance) ? :covariance : :correlation
  @matrix=matrix
  @cases=cases
  @means=means
  if variable_names.nil? 
    @variables=@matrix.fields if @matrix.respond_to? :fields
  else
    @variables=variable_names
  end
end

#dup ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 30

def dup
  mod=Model.new(@opts)
  if @data_type==:raw
    mod.data_from_dataset(@ds)
  else
    mod.data_from_matrix(@matrix,:type=>@data_type,:cases=>@cases, :means=>@means) 
  end
  mod.latents=latents
  mod.manifests=manifests
  if @paths
    @paths.each_pair do |k,v|
      mod.add_raw_path(k[0],k[1],v[:arrow],v[:label],v[:free], v[:value])
    end
  end
  mod
end

#get_label(key) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 184

def get_label(key)
  @paths[key][:label]
end

#infer_latents ⇒ Object

Latents will be any variable set on a path not present on @variables



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# File 'lib/statsample/sem/model.rb', line 177

def infer_latents
  variables_on_paths-@variables
end

#infer_manifests ⇒ Object

Latens will be any variable set on path present on @variables



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# File 'lib/statsample/sem/model.rb', line 181

def infer_manifests
  variables_on_paths & @variables
end

#k ⇒ Object

Number of variables on model



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# File 'lib/statsample/sem/model.rb', line 172

def k
  variables_on_paths.size
end

#latents(*argv) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 187

def latents(*argv)
  if argv.size==0
    if @latents.nil? and @paths.size>0 and !@data_type.nil? 
      @latents=infer_latents
    end
    @latents
  elsif argv[0].is_a? Array 
    @latents=argv[0]
  else
    @latents=[argv]
  end
end

#latents=(argv) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 199

def latents=(argv)
  @latents=argv
end

#make_null ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 46

def make_null
  # Get current variables
  vars=variables_on_paths
  @paths.clear
  vars.each do |v|
    if @variables.include? v
      free=true
      value=nil
    else
      free=false
      value=1.0
    end
    add_raw_path(v,v,2,"var #{v}",free,value)
  end
end

#manifests(*argv) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 203

def manifests(*argv)
  if argv.size==0
    if @manifests.nil? and @paths.size>0 and !@data_type.nil? 
      @manifests=infer_manifests
    end
    @manifests
  elsif argv[0].is_a? Array 
    @manifests=argv[0]
  else
    @manifests=[argv]
  end
end

#manifests=(argv) ⇒ Object 



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# File 'lib/statsample/sem/model.rb', line 215

def manifests=(argv)
  @manifests=argv
end

#path(opts) ⇒ Object

Set one or more paths. Based on OpenMx mxPath method.

Options:

  • :from : String or Array. sources of new paths

  • :to : String or Array. sinks of new paths

  • :all : bool. If you, connect all sources to all sinks. If false,

connect one-on-one sources to sinks if both are arrays, one source to many sinks if :from is a String and :to is an Array

  • :arrows : 1 for regression, 2 for variance-covariance. See rules

for specific automatic setting

  • :free : Indicates whether paths are free or fixed. By default, true

  • :values : The starting values of the parameters

  • :labels : The names of paths

Rules

  • from : variance-> from and to equal, label equal to “s^2 NAME_OF_FIELD”, arrows=2, free=>true

  • from and to: regression -> label equal to “FROM->TO”, arrows=1, free=>true

  • from, to, arrows -> label equal to “FROM->TO” if arrows=1,

“FROM<->TO” if arrows=2, free=>true

  • free=false -> requires values for each from - to value



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# File 'lib/statsample/sem/model.rb', line 104

def path(opts)
  raise "Requires at least :from option" unless opts.has_key? :from
  
  free=true
  all=false
  
  from=opts[:from]
  to=opts[:to]
  
  all=opts[:all] if opts.has_key? :all
  free=opts[:free] if opts.has_key? :free

  labels=opts[:labels]
  arrows=opts[:arrows]
  
  values=opts[:values]
  from=[from] if from.is_a? String
  to||=from
  to=[to] if to.is_a? String
  
  if from==to # variances
    arrows||=2
    labels_2=Array.new(from.size)
    
    from.each_with_index do |f,i|
      labels_2[i]=(labels.nil? or !labels.respond_to?:[] or labels[i].nil?) ? "var #{f}" : labels[i]
    end
    
    from.each_with_index do |f,i|
      add_path(f,f,arrows,free,values, labels_2,i)
    end
  else # regression and covariances
    arrows||=1
    i=0
    all=true if from.size==1 or to.size==1
    if all
      from.each do |f1|
        to.each do |f2|
          add_path(f1,f2,arrows,free,values,labels,i)
          i+=1 
        end
      end
    else
      raise ":from and :to should be the same size" if from.size!=to.size
      from.size.times.each do |i|
        add_path(from[i],to[i],arrows,free,values,labels,i)
      end
      
    end
    
  end
  
  
end

#variables_on_paths ⇒ Object

Total number of variables



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# File 'lib/statsample/sem/model.rb', line 163

def variables_on_paths
  out=Array.new
  @paths.keys.each {|k|
    out << k[0] unless out.include? k[0]
    out << k[1] unless out.include? k[1]
  }
  out
end