Class: CTioga2::Data::DataStack

Inherits:
Object
  • Object
show all
Includes:
Log
Defined in:
lib/ctioga2/data/stack.rb

Overview

This is the central class for acquisition and handling of Dataset objects, retrieved from from a Backends::BackendFactory.

todo provide real stack manipulation functions such as

  • interpolation: pops the last object from the stack and add its interpolated values on the element before.

  • mathematical functions on each column (DataColumn)

  • other stack-based operations.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Log

context, debug, error, fatal, #format_exception, #identify, info, init_logger, log_to, logger, set_level, #spawn, warn

Constructor Details

#initialize ⇒ DataStack

Creates a new DataStack object.



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# File 'lib/ctioga2/data/stack.rb', line 65

def initialize
  @stack = Array.new

  @named_datasets = Hash.new

  # Defaults to the 'text' backend
  @backend_factory = Data::Backends::BackendFactory.new('text')

  # Probably a bit out of place...
  csv = 
    Cmd.new('csv', nil, '--csv', []) do |plotmaker|
    plotmaker.interpreter.
      run_commands("text /separator=/[,;]/")
  end
  
  csv.describe("reads CSV files", 
                      <<"EOH", "backend-text")
Now parse the following data files as CSV.

# text /separator=/[,;]/
EOH
end

Instance Attribute Details

#backend_factory ⇒ Object

The BackendFactory used for retrieving data from named sets.



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# File 'lib/ctioga2/data/stack.rb', line 47

def backend_factory
  @backend_factory
end

#dataset_hook ⇒ Object

A hook executed every time a dataset is pushed unto the stack using #add_dataset.

todo this string is parsed for each call to #add_dataset. Perhaps it would be good to provide a way to record a Command call, without parsing it from scratch ???

Although, with variables, that could be interesting to reparse everytime, since any change in the variables would be taken into account.



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# File 'lib/ctioga2/data/stack.rb', line 62

def dataset_hook
  @dataset_hook
end

#named_datasets ⇒ Object

Named datasets



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# File 'lib/ctioga2/data/stack.rb', line 50

def named_datasets
  @named_datasets
end

#stack ⇒ Object

The array containing all the Dataset used so far.



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# File 'lib/ctioga2/data/stack.rb', line 44

def stack
  @stack
end

Instance Method Details

#add_datasets(datasets, options = {}) ⇒ Object

Adds a series of datasets, and perform various operations according to the hash options:

  • ‘name’ to name each element added to the stack. A %d will be replaced by the number of the dataset within the ones just added.

Additional members of the Hash are simply ignored.



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# File 'lib/ctioga2/data/stack.rb', line 115

def add_datasets(datasets, options = {})
  i = 0
  for ds in datasets
    store_dataset(ds, options['ignore_hooks'])

    # Selection
    if options['where']
      ds.select_formula!(options['where'])
    end

    if options['name']
      @named_datasets[options['name'] % [i]] = ds
    end
    i += 1
  end
end

#add_to_dataset_hook(commands) ⇒ Object

Appends a set of commands to the dataset hook



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# File 'lib/ctioga2/data/stack.rb', line 223

def add_to_dataset_hook(commands)
  if @dataset_hook
    @dataset_hook << "\n#{commands}"
  else
    @dataset_hook = commands
  end
end

#concatenate_datasets(datasets, name = nil) ⇒ Object

Add all the given datasets to the current one.



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# File 'lib/ctioga2/data/stack.rb', line 242

def concatenate_datasets(datasets, name = nil)
  ds = @stack.pop
  raise "Nothing on the stack" unless ds

  for ds2 in datasets
    ds << ds2
  end
  @stack.push(ds)
  # Name the dataset
  @named_datasets[name] = ds if name
end

#dataset_xref(spec) ⇒ Object

Returns the [dataset, index, name] of the given dataset



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# File 'lib/ctioga2/data/stack.rb', line 140

def dataset_xref(spec)
  ds = nil
  index = nil
  name = nil
  if spec.is_a? Numeric or spec =~ /^\s*-?\d+\s*$/
    spec = spec.to_i
    index = spec
    name = nil
    ds = @stack[index]
    for k,v in @named_datasets
      if v == ds
        name = k
      end
    end
  else
    if @named_datasets.key? spec
      name = spec
      ds = @named_datasets[spec]
      i = 0
      for d in @stack
        if d == ds
          index = i
        end
        i += 1
      end
    else
      raise "Unkown named dataset from the stack: '#{spec}'"
    end
  end
  return [ds, index, name]
end

#drop_from_stack(spec) ⇒ Object

Drops the dataset corresponding to the given spec from the stack



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# File 'lib/ctioga2/data/stack.rb', line 297

def drop_from_stack(spec)
  xr = dataset_xref(spec)
  if xr[1]                # But that should always be the case ?
    @stack.delete_at(xr[1])
  else
    warn { "For some reason, dataset '#{spec}' is not in the stack !"}
  end
  if xr[2]
    @named_datasets.delete(xr[2])
  end
end

#get_datasets(set, options = {}) ⇒ Object

Performs expansion on the given set with the current backend, retrieves corresponding Dataset objects, pushes them onto the stack and returns them.



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# File 'lib/ctioga2/data/stack.rb', line 91

def get_datasets(set, options = {})
  backend = @backend_factory.specified_backend(options)
  sets = backend.expand_sets(set)
  datasets = []
  for s in sets
    begin
      datasets << backend.dataset(s)
    rescue Exception => e
      error { "Could not load dataset #{s} -- #{e}" }
      debug { "#{e.backtrace.join("\n")}" }
    end
  end
  add_datasets(datasets, options)
  return datasets
end

#last ⇒ Object

Returns the last Dataset pushed onto the stack.



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# File 'lib/ctioga2/data/stack.rb', line 265

def last
  return @stack.last
end

#latest_datasets(opts) ⇒ Object

Returns a list of datasets, either a named dataset, or the last datasets from the stack



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# File 'lib/ctioga2/data/stack.rb', line 205

def latest_datasets(opts)
  if opts['which']
    if opts['number']
      warn { "Cannot use both which and number" }
    end
    datasets = [ specified_dataset(opts) ]
  else
    nb = opts['number'] || 2
    if @stack.size < nb
      raise "Not enough datasets on the stack"
    end
    datasets = @stack[(- nb).. -2]
    datasets.reverse!
  end
end

#merge_datasets_into_last(datasets, columns = [0], precision = nil) ⇒ Object

Merges one or more datasets into the last one.

The last dataset of the stack is overwritten.



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# File 'lib/ctioga2/data/stack.rb', line 257

def merge_datasets_into_last(datasets, columns = [0], precision = nil)
  ds = @stack.pop
  raise "Nothing on the stack" unless ds
  ds.merge_datasets_in(datasets, columns, precision)
  @stack.push(ds)
end

#print_dataset(dataset, io) ⇒ Object

Writes the contents of the the given dataset (a DataSet object) to the given io stream.



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# File 'lib/ctioga2/data/stack.rb', line 233

def print_dataset(dataset, io)
  io.puts "# #{dataset.name}"
  io.puts "# #{dataset.column_names.join("\t")}"
  dataset.each_values do |i, *vals|
    io.puts vals.join("\t")
  end
end

#show ⇒ Object

Displays the contents of the stack



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# File 'lib/ctioga2/data/stack.rb', line 270

def show
  STDERR.puts "Stack contents"
  i = 0
  # Swap the named dataset stuff
  ## @todo Maybe a hash pair should be maintained in permanence ?
  rev = {}
  for k,v in @named_datasets
    rev[v] = k
  end

  for ds in @stack
    name = rev[ds]
    if name
      name = "(named: '#{name}')"
    else
      name = ""
    end
    
    pref = sprintf("#%-2d %-3d:", i, - @stack.size + i)
    
    STDERR.puts " * #{pref} #{ds.name} -- #{ds.ys.size + 1} columns, #{ds.x.size} points #{name}"
    i += 1
  end
end

#specified_dataset(options, full = false) ⇒ Object

Gets a dataset from the given options hash. If a ‘which’ key is present, it is used as an argument for #stored_dataset; else, -1 is used.



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# File 'lib/ctioga2/data/stack.rb', line 175

def specified_dataset(options, full = false)
  spec = if options && options['which']
           options['which']
         else
           -1
         end
  xr = dataset_xref(spec)
  return (full ? xr : xr[0])
end

#store_dataset(dataset, ignore_hooks = false) ⇒ Object

Adds a Dataset object onto the stack, running hooks if necessary.

Makes use of Plotmaker.plotmaker



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# File 'lib/ctioga2/data/stack.rb', line 189

def store_dataset(dataset, ignore_hooks = false)
  @stack << dataset
  if @dataset_hook && (! ignore_hooks)
    # \todo error handling
    begin
      PlotMaker.plotmaker.interpreter.run_commands(@dataset_hook)
    rescue Exception => e
      error { "There was a problem running the dataset hook '#{@dataset_hook}', disabling it" }
      @dataset_hook = nil
      info { "-> '#{format_exception e}'" }
    end
  end
end

#stored_dataset(spec) ⇒ Object

Returns the stored dataset, either using its index in the stack, or its name in the dataset.



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# File 'lib/ctioga2/data/stack.rb', line 134

def stored_dataset(spec)
  return dataset_xref(spec)[0]
end