This page will briefly describe how to use this tool to generate sparse formats for the default matrix, view and plot the matrix elements, and download the matrix in coordinate format.
While using the tool, click on any blue link to learn more about a particular subject. For the particular example in this tutorial, we use the default values for each of the text fields. Once you gain familiarity with the tool, however, feel free to choose other values to see how your results change.
Upload Data
After clicking the 'Launch Sparse Matrix Tool' button located on the main tool page, the sparse matrix tool will open in a separate window as shown in the image below.
In this panel, you either select to use the default matrix or to launch the upload tool to upload your own matrix. For this tutorial we are using the default matrix, so click the Use Default Matrix button. Once the default matrix has been stored, click the Next button or Your Input panel in the Task List to proceed to the next step.
Your Input
In this panel, you have the option of reviewing the input matrix, either by row or column. The default is to view the elements of the first row of the matrix.
Click the View Data button to view the first row of the default matrix input data. The following window will appear:
Leave the Review Input window up and return to the Your Input panel of the Sparse Matrix Tool. Change the Value field to 2 to view the data in the second row. Click the View Data button. The following will appear in the Review Input window:
Use the Back and Forward buttons in the Review Input window to compare the data in rows 1 and 2 of your input matrix. You may view other input data by changing the View Data By dropdown menu and the Value field. Once you have finished reviewing the data in the input matrix, close the Review Input window by clicking the Close button and click the Next button in the Your Input panel in the Sparse Matrix Tool to proceed to the next step.
Output Matrix
In the Output Matrix panel, a table of matrix parameters appears. You may view the data by row or column and you may plot the nonzero elements:
Viewing the nonzero elements by row and column is exactly analogous to how you reviewed the input, so we won't review that. Instead, we plot the matrix. To do this, click the 'Plot Matrix' button. The following graph appears in which the y-axis is the rows of the matrix, the x-axis is the columns, and the solid squares are the nonzero elements:
Once you have viewed the graph, click the Close button to close the window and the Next button in the tool panel to download your matrix.
Download Matrix
You are now ready to download your matrix. In this panel links are presented for both ascii and xml formats of the three storage schemes. We are focusing on the coordinate matrix scheme in this tutorial, so click on the link below 'Coordinate Matrix' labelled 'xml'.
You will be presented with a window asking you if you'd like to open the file or save it to disk. Select save, then select where you'd like to save the file on your computer. The file will be downloaded. You can now view your coordinate matrix in xml format.
To download the ascii (simple text) format of the coordinate matrix, click the link below the Coordinate Matrix bullet labelled 'ascii' and repeat the same steps used to download the xml.
Challenge
Can you download your matrix in the Yale Sparse and Compressed Sparse Row storage schemes?
