Class: CTioga2::Data::DataPoint
- Inherits:
-
Object
- Object
- CTioga2::Data::DataPoint
- Defined in:
- lib/ctioga2/data/point.rb
Overview
This class represents a datapoint, ie. an index in a given DataSet.
Instance Attribute Summary collapse
-
#dataset ⇒ Object
The Dataset object the point is in.
-
#index ⇒ Object
The index of the data point within the Dataset.
Class Method Summary collapse
-
.from_text(plotmaker, text) ⇒ Object
Creates a DataPoint object based on the following text specification.
Instance Method Summary collapse
-
#dx(navg = 3) ⇒ Object
Returns the average value of the difference between two consecutive X values.
-
#initialize(dataset, index) ⇒ DataPoint
constructor
Creates a DataPoint with the given information.
-
#slope(navg = 3) ⇒ Object
Returns the value of the slope around the datapoint.
-
#x_val(navg = 3) ⇒ Object
Returns the averaged X value around the datapoint.
-
#y_val(navg = 3) ⇒ Object
Returns the averaged Y value around the datapoint.
Constructor Details
#initialize(dataset, index) ⇒ DataPoint
Creates a DataPoint with the given information.
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# File 'lib/ctioga2/data/point.rb', line 36 def initialize(dataset,index) @dataset = dataset @index = index end |
Instance Attribute Details
#dataset ⇒ Object
The Dataset object the point is in
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# File 'lib/ctioga2/data/point.rb', line 30 def dataset @dataset end |
#index ⇒ Object
The index of the data point within the Dataset
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# File 'lib/ctioga2/data/point.rb', line 33 def index @index end |
Class Method Details
.from_text(plotmaker, text) ⇒ Object
Creates a DataPoint object based on the following text specification. It needs a reference to a plotmaker, since it accesses the data stack.
Specification: (<em>dataset</em>)?(relative|@index)
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# File 'lib/ctioga2/data/point.rb', line 46 def self.from_text(plotmaker, text) if text =~ /^(?:\s*\{([^}]+)\})?\s*(?:([.\d]+)|@(\d+))\s*$/ which = $1 || -1 if $2 rel = Float($2) else idx = $3.to_i end dataset = plotmaker.data_stack.stored_dataset(which) if ! dataset raise "Invalid or empty dataset: #{which}" end if rel idx = (rel * dataset.x.values.size).to_i end return DataPoint.new(dataset, idx) else raise "Not a valid datapoint specification: '#{text}'" end end |
Instance Method Details
#dx(navg = 3) ⇒ Object
Returns the average value of the difference between two consecutive X values
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# File 'lib/ctioga2/data/point.rb', line 135 def dx(navg = 3) xvect = @dataset.x.values di = (navg-1)/2 navg = 2*di + 1 idx = usable_index(di, xvect.size) return (xvect[idx+di]-xvect[idx-di])/navg end |
#slope(navg = 3) ⇒ Object
Returns the value of the slope around the datapoint. This is obtained using a linear regression, so it should be rather reliable.
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# File 'lib/ctioga2/data/point.rb', line 107 def slope(navg = 3) xvect = @dataset.x.values yvect = @dataset.y.values di = (navg-1)/2 navg = 2*di + 1 idx = usable_index(di, xvect.size) sx = 0 sxx = 0 sxy = 0 sy = 0 (idx-di).upto(idx+di) do |i| sx += xvect[i] sy += yvect[i] sxx += xvect[i]**2 sxy += xvect[i] * yvect[i] end if sxx*navg == sx*sx return 1 else return (sxy * navg - sx*sy)/(sxx * navg - sx*sx) end end |
#x_val(navg = 3) ⇒ Object
Returns the averaged X value around the datapoint
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# File 'lib/ctioga2/data/point.rb', line 73 def x_val(navg = 3) xvect = @dataset.x.values di = (navg-1)/2 navg = 2*di + 1 idx = usable_index(di, xvect.size) xval = 0 (idx-di).upto(idx+di) do |i| xval += xvect[i] end return xval/(navg) end |
#y_val(navg = 3) ⇒ Object
Returns the averaged Y value around the datapoint
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# File 'lib/ctioga2/data/point.rb', line 90 def y_val(navg = 3) yvect = @dataset.y.values di = (navg-1)/2 navg = 2*di + 1 idx = usable_index(di, yvect.size) yval = 0 (idx-di).upto(idx+di) do |i| yval += yvect[i] end return yval/(navg) end |