Technique Regressions Chapter
Applicability: Cranium, Synapse (core versions 0326+)

The Technique Regressions Chapter is found in modeling documents. The chapter manages entity lists, compilation code, regression values, and regression results. The chapter also provides commands for regressing values into a technique model.

Typical Usage
  • Calculate the Antoine parameters for a fragrance chemical that are applicable at lower temperatures. (See video.)
  • Determine the van Laar binary interaction parameters for a mixture of chemicals with known activity coefficient data. (See video.)
  • Add a contribution for a new silicon group to a commonly used group contribution technique using data on a set of similar chemicals. (See video.)
Chapter Sections

The chapter's datapane is divided into seven sections:

Section Description
Source Knowledge Base Section used to record the knowledge base that will be used as the source of all entities, physical property data, and estimation techniques as well as the destination of newly regressed variable values.
Regression Specification Section enables you to specify the entity type, the entities, and the compilation function used to collect values to be used in the regression.
Regression Values Section displays values for the the compiled y and z regression variable values. Provides you with analysis tools for identifying duplicate rows, correlated variables, values with minimal variation.
Technique Variables Section displays the technique variables to be used in the regression along with their initial values. Variables can be entered for parameters, binary interaction parameters, and group contributions.
Final Variables Values Section displays the final optimal values of the parameters, binary interaction parameters, and group contributions specified in the regression. Values presented for both limiting z variables and x variables.
Regression Results Section displays the regression's summary statistics, parity plots, histograms, and residuals. You can use these values to determine the quality of the regression as well as identify ways in which to improve the regression.
General Notes Section used to store any general notes about the current regression. Typically, this section is used to detail the criteria used to select regression values and details about the technique transfer specifications.
Associated Documents Section used to store links to any documents associated with the current regression.
Chapter Commands

The Technique Regressions chapter has commands for compiling regression values, regressing these values into a technique's model, transferring these regressed variable values to source estimation techniques, and reporting these results. These commands are available from the chapter's Commands menu.

  • Open Source Knowledge Base: opens the knowledge base whose name is stored in the Source Knowledge Base Section.
  • Report Regression Properties: activates the Report Properties Dialog that enables you to select regression properties and attributes to add to an open Report Document. (Also see documentation on Reporting Properties.
  • Compile Regression Values: activates the Regression Values Compilation Dialog: which compiles regression values by executing the compilation code on each entity.
  • Clear Regression Results: removes all regressed coefficients, statistics, graphs, and residuals from the current regression. Clearing a regression is typically necessary before input values can be changed.
  • Regress Variable Values: activates the Technique Regression Dialog which enables you to regress optimal parameters, binary interaction parameters and group contributions from the entered regression values.
  • Transfer Values: activates the Technique Variables Transfer Dialog which enables you to copy regressed parameters, bips, and group contributions into one or more estimated techniques in the source knowledge base.
Common Commands

The menubar provides numerous other commands for navigation, bookmarking, file operations, units conversion, etc. See the documentation on Common Commands for details.

Related Documentation
Topic Description
Getting Started using Synapse provides a quick tour of Synapse's capabilities including examples of chemical product design.
Getting Started using Cranium provides a quick tour of Cranium's capabilities including a discussion of structure editing.
Estimating Chemical Properties a short video demonstrating how to estimate the physical properties of chemicals using either Synapse or Cranium.
Estimating Mixture Properties a short video demonstrating how to estimate the physical properties of mixtures using either Synapse or Cranium.