Minimizemodel and Variableselectiongui: Difference between pages

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===Purpose===
==Introduction==


Shrinks model by removing non-critical information.
The Variable Selection panel contains an interface to several methods for performing variable selection. The goal is to find subsets of variables that improve predictions when compared to using all variables. This interface has several different methods available. Finding the best method and options settings will take some experimentation. Use links below for more information on particular methods.


===Synopsis===
==Methods==


:mm = minimizemodel(model) %compress model
* Automatic (VIP or sRatio)
:minimizemodel(model)      %display size information only
* GA - Genetic Algorithm
* iPLS - Interval PLS
* rPLS - Recursive PLS
* sRatio - Selectivity Ratio
* VIP - Variable Importance in Projection


===Description===
==Work Flow==


Models contain both the information necessary to apply that model to new data and also the results calculated with the model was built (such as scores, cross-validation results, Hotellings T^2, sum squared residuals from the calibration samples.) Although this additional calibration sample information is necessary to review the model results, they are not necessary to apply the model to new data.
* <u>Select a Method</u> - Select a method from the drop-down menu. Options for the method will be displayed. If a previous calculation has been done, the results of it will be displayed.  
 
* <u>Adjust Options</u> - By default, a simplified set of options are displayed. If the "Show All Options" checkbox is selected then all available options will be displayed. Depending on the options set, a particular method can take an extended amount of time to complete. For example, decreasing the window width in GA will increase the amount of time it takes to complete. See documentation for more details on optional settings.
MINIMIZEMODEL attempts to compress a model by removing the fields which are not strictly necessary to apply the model. Such compression will prevent the direct comparison of new sample results to calibration sample results, but the model will still be functional for on-line use, for example.
* <u>Run Variable Selection</u> - Clicking the "Execute" button will run the current variable selection method with values specified in the options. A waitbar will be displayed indicating the method is running. Some methods will display a waitbar with a message indicating it can be closed to cancel execution. NOTE: It can take some time for the method to finish a calculation loop and identify the user has canceled. If "Show Plots" is checked then any additional plots will be displayed in separate windows. This is useful for GA as it will show progress of the calculation.
 
* <u>View Results</u> - When a calculation is complete the selected variables will be displayed under a plot of the data mean as green bars.
The extent of compression varies greatly between model types and will generally be more effective on models built from large numbers of samples and fewer variables as compared to models built from large numbers of variables and fewer samples.
 
If no outputs are requested, the sizes of all model fields with more than 100 bytes in size are returned.
 
====Inputs====
 
* '''model''' = standard model structure to compress.
 
====Outputs====
 
* '''mm''' = minimized model.
 
 
===See Also===
 
[[compressmodel]], [[modelstruct]]

Revision as of 14:24, 11 January 2018

Introduction

The Variable Selection panel contains an interface to several methods for performing variable selection. The goal is to find subsets of variables that improve predictions when compared to using all variables. This interface has several different methods available. Finding the best method and options settings will take some experimentation. Use links below for more information on particular methods.

Methods

  • Automatic (VIP or sRatio)
  • GA - Genetic Algorithm
  • iPLS - Interval PLS
  • rPLS - Recursive PLS
  • sRatio - Selectivity Ratio
  • VIP - Variable Importance in Projection

Work Flow

  • Select a Method - Select a method from the drop-down menu. Options for the method will be displayed. If a previous calculation has been done, the results of it will be displayed.
  • Adjust Options - By default, a simplified set of options are displayed. If the "Show All Options" checkbox is selected then all available options will be displayed. Depending on the options set, a particular method can take an extended amount of time to complete. For example, decreasing the window width in GA will increase the amount of time it takes to complete. See documentation for more details on optional settings.
  • Run Variable Selection - Clicking the "Execute" button will run the current variable selection method with values specified in the options. A waitbar will be displayed indicating the method is running. Some methods will display a waitbar with a message indicating it can be closed to cancel execution. NOTE: It can take some time for the method to finish a calculation loop and identify the user has canceled. If "Show Plots" is checked then any additional plots will be displayed in separate windows. This is useful for GA as it will show progress of the calculation.
  • View Results - When a calculation is complete the selected variables will be displayed under a plot of the data mean as green bars.