def add_feature feature, value, dataset
      unless feature.name == "ATOMIC COMPOSITION" or feature.name == "FUNCTIONAL GROUP" # redundand
        case feature.category
        when "P-CHEM"
          properties[feature.id.to_s] ||= []
          properties[feature.id.to_s] << value
          properties[feature.id.to_s].uniq!
        when "Proteomics"
          properties[feature.id.to_s] ||= []
          properties[feature.id.to_s] << value
          properties[feature.id.to_s].uniq!
        when "TOX"
          if feature.name.match("Cell Viability Assay") and !feature.name.match("SLOPE") # -log10 transformation
            value = -Math.log10(value)
            feature.unit = "-log10(#{feature.unit})" unless feature.unit.match "log10"
            feature.warnings += ["-log10 transformed values"]  unless feature.warnings.include? "-log10 transformed values"
            feature.save
          end
          dataset.add self, feature, value
        else
          warn "Unknown feature type '#{feature.category}'. Value '#{value}' not inserted."
        end
        dataset_ids << dataset.id
        dataset_ids.uniq!
      end
    end
def add_feature feature, value, dataset
      unless feature.name == "ATOMIC COMPOSITION" or feature.name == "FUNCTIONAL GROUP" # redundand
        case feature.category
        when "P-CHEM"
          properties[feature.id.to_s] ||= []
          properties[feature.id.to_s] << value
          properties[feature.id.to_s].uniq!
        when "Proteomics"
          properties[feature.id.to_s] ||= []
          properties[feature.id.to_s] << value
          properties[feature.id.to_s].uniq!
        when "TOX"
          if feature.name.match("Cell Viability Assay") and !feature.name.match("SLOPE") # -log10 transformation
            value = -Math.log10(value)
            feature.unit = "-log10(#{feature.unit})" unless feature.unit.match "log10"
            feature.warnings += ["-log10 transformed values"]  unless feature.warnings.include? "-log10 transformed values"
            feature.save
          end
          dataset.add self, feature, value
        else
          warn "Unknown feature type '#{feature.category}'. Value '#{value}' not inserted."
        end
        dataset_ids << dataset.id
        dataset_ids.uniq!
      end
    end
Add (measured) feature values
 @param [OpenTox::Feature]
 @param [TrueClass,FalseClass,Float]
 @param [OpenTox::Dataset]