Criteria

The Criteria dialog provides two ways of excluding data that you do not want to display on a plot.

 

Criteria Dialog

To open the Criteria dialog, click on an existing plot. In the Property Manager, click on the Clipping tab. Click on the Set button next to the Criteria command.

 


Use the
Criteriadialog to exclude data that you do not want to plot.

 

Null Criteria

A null value is a value that is treated as missing data. For example, if the number -9999 indicates no data in your data file, it is usually treated as a valid number when plotting graphs. By checking the Use NULL criteria option, you can indicate that -9999 should be treated as a null field so these values are not plotted on the graph.

 

To treat a number as a null value:

  1. Click on a plot to select it.

  2. In the Property Manager, click on the Data Limits tab.

  3. Check the box next to the Use criteria command.

  4. Click the Setbutton next to the Criteria command to open the Criteria dialog.

  5. Check the box next to the Use NULL criteria option.

  6. Click the Value button. The Enter NULL Value dialog opens.

  7. Type a number in the NULL Valuebox and click OK.

  8. Click OK in the Criteria dialog to return to the plot. The points with the NULL valuewill not be drawn on the plot.

 

To treat a data range as null values:

  1. Click on a plot to select it.

  2. In the Property Manager, click on the Data Limits tab.

  3. Check the box next to the Use criteria command.

  4. Click the Setbutton next to the Criteria command to open the Criteria dialog.

  5. Check the box next to the Use NULL criteria option.

  6. Click the Range button.

  7. Type a low and high value in the Range dialog and click the OK button.

  8. Click the OK button in the Criteria dialog to return to the plot.

 

You can add several values as null values. Letters (a-z), numbers with symbols (e.g., 50%), and rows containing blank cells are not treated as numbers and are not plotted on a graph.

 

Specifying Data Columns

By default, only the plotted data columns are used when determining if a point should have the null criteria applied. To use additional columns, clear the Data columns only box. Click the Select columns button and select columns to check for null values.

 

Column Criteria

The column criteria method is a way to select data based on entries in an additional column. For example, a data file has five sampling locations labeled L1 through L5. To create a plot containing only the third sampling location, L3, you would use column criteria. Numeric values and text may be used as column criteria.

 

To use column criteria:

  1. Click on a plot to select it.

  2. In the Property Manager, click on the Data Limits tab.

  3. Check the box next to the Use criteria command.

  4. Click the Setbutton next to the Criteria command to open the Data Limits dialog.

  5. Check the Use column criteria box.

  6. Click the Add button. The Enter Criteria Value dialog appears.

  7. Type the criteria value into the Enter Criteria Value dialog and click the OK button.

  8. Click the OK button in the Criteria dialog to return to the plot.

 

Criteria Tips

Both null and column criteria can be used together in a single plot.

 

If no data plots after you click the OK button in the Criteria dialog, check the columns for the null criteria to ensure that only the appropriate columns are selected, or check the data file to ensure that the column criteria value is in the worksheet.

 

 

See Also

Standard Axes

Tick Marks

Data Limits Properties