Constructing a PLS model

To construct a PLS model:

1. On the Troubleshooting Project Bar, click on the modeling button. Note this button is only available after the previous steps have been completed.

2. From the modeling view click on the Construct button in the PLS group.

3. Select the X-field(s) to add and click on the add (>) button to add the field to the selection.  These fields are also referred to as model inputs.

4. Select the Y-field(s) to add and click on the add (>) button to add the field to the selection.  These fields are also referred to as model targets.

   1. Remove field(s) by selecting the a field and click on the remove (<) button.

   2. To add all fields to the selection, click on the add all (>>) button.

   3. To remove all fields from the selection, click on the remove all (<<) button.

5. X Variance contribution: This defines how much of the process variance needs to be explained by the input fields. This number will influence the number of input fields selected - the greater the x variance contribution, the more inputs fields need to be selected.

6. Normalize data: Normalizing data is the conversion of all data points to a value of between 0 - 1, meaning that different variables can be compared without the influence of scale and units. You don't need to normalize the data if the data is all of the same variable, thus if you know that all the units and the scale is already the same.

7. Click [Ok] when completed. The model will be generated, and the score and SPE plots will be shown.

By clicking on [Modeling] on the Troubleshooting Project Bar, the attributes of the PLS model will be listed. You will see the number of model components that explains the requested X Variance contribution. The actual  Variance contribution will differ slightly, explaining how much of the variance is actually explained by the number of X variables, or model input fields. For the record, the data selection and if the data was normalized is also listed.

Reconstruct PLS

This option allows the user to reconstruct the PLS model with different criteria for model configuration.

1. From the modeling view, click on the Reconstruct PLS button

2. Follow the steps provided for constructing a PLS model as provided in the above section.

3. Click on Ok when done.

Related topics:

• Viewing a PLS model