MIA Toolbox PCA Quick Start

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Revision as of 16:17, 9 October 2009 by imported>Scott
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Previous Topic: Loading Data

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This example uses the smbread dataset. Load smbread by clicking on Load Demo Data in the tree, then Swedish Knackerbrod. This will load the data into Image Manager. Click on the item in the Loaded Images section to view it and make it the current selected image. Next, click on the export to Analysis button. This will open the Analysis GUI and load smbread.

by selecting File/Import Data.../Workspace/MAT file. Click the From File button, type "arch" into the File: text box, and then hit the Return key. Because arch is on the path, the importer will locate the arch.mat file and show its variables. Click Load and the data will be available in the "Browser".

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Once data has been loaded into the workspace, there are several ways to begin building a model. For analysis tools like PCA where only an X block is required, you can right-click on the data icon in the Browser to reveal a list of analysis options. You can also drag the given data to an analysis method shortcut, such as the Decompose PCA shortcut.

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The Analysis GUI will then appear with the given data already loaded. (The large X (block) button in the Analysis GUI will appear depressed indicating the data is loaded - passing the cursor over the button will provide a summary of the X block data.)

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While each analysis type has its own nuances, in general the steps to build a model are:

  1. load the data
  2. view the data
  3. choose preprocessing
  4. select the type of cross-validation to use (if any is desired - see Using Cross-Validation)
  5. build the model
  6. review the model

There is more than one way to accomplish each of the above steps. For example, preprocessing can be set for the X block by

  • clicking the "Choose Preprocessing" button in the Analysis Flowchart
  • clicking the P button next to the X button
  • select "Preprocess" menu item

(Hint: Once selected, use the Preprocess/X-block and Preprocess/Y-block menus to save the current preprocessing as the default.)

You can quickly view your data by right-clicking on the appropriate button (X or Y) and then select "Plot Data"

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Perhaps the quickest way for new users to complete the remaining steps to build the model is to use the flowchart.

Next Topic: Review Results