Modifying a chart

Once a chart has been created, you can further modify it by accessing its shortcut menu wizard which is composed by a set of screens that are similar to the wizard screens used to create the chart. For example, you can change the data used by the chart, modify the chart type, and so on.

To modify a chart after it has been created:

  1. Right-click the chart and select Chart Wizard from the shortcut menu to display the Chart Wizard.
  2. In the Data screen, specify a new data source for the chart if required.
  3. In the Type screen, specify the type of the chart.

    If you want to change the chart type, you may need to first remove all chart data. Specially, if you change a combo type to a single type or vice versa, JReport will prompt you to make sure because all chart data will be removed automatically.

  4. In the Display screen, specify the fields to be displayed on the chart.
  5. In the Layout screen, specify settings for the chart elements.
  6. In the Style screen, select a style for the chart.
  7. When done, click Finish to accept the changes.

For more detailed steps about how to define a chart, see Inserting a chart.

See also Chart Wizard for details about options in the wizard.

Notes:

After finishing the modification, you can also apply some filter conditions to narrow down the records displayed in the chart the same as you do for a table (for details, see Filtering the data). However, if the chart is created on an HDS, the conditions you define in the Format Filter dialog will not be applied when the chart runs due to the specialty of HDS. Therefore, if you want to filter the data displayed in such kind of charts, you need to make use of the dataset filter.

Defining special groups for category/series values

You can define how to group values on the category/series axis of a chart. To do this:

  1. In the Display screen of the Chart Wizard, click the Special Group button below the Category/Series box to bring out the User Defined Group dialog. See the dialog.

  2. Click the Add button to add a grouping line and specify the Group Name, Operator and Operand as required. Repeat this to add more group criteria.

    For example, if you place a field named Score for grouping which contains student scores that range from 0 to 100, and you want to group the students in 5 ranks, namely rank A: 90~100, B: 80~89, C: 70~79, D: 60~69, and E: 0~59. You can set the groups as follows:

    Group Name Operator Operand
    A between Op1: 90, Op2: 100
    B between Op1: 80, Op2: 89
    C between Op1: 70, Op2: 79
    D between Op2: 60, Op2: 69
    E <= 59

    There will be five groups in the order from A to E. If you want to change the order of the groups, you can also do so via the User Defined Group dialog.

  3. Check Keep values outside of the range in special group checkbox if you want to put the values that are not included in the specified criteria in a new special group, and then provide a name for the special group in the Special Group Name text field.
  4. Click OK to accept the settings.
  5. When done, click Finish in the Chart Wizard to apply the changes.

See also User Defined Group dialog for details about options in the dialog.

Grouping data on the category/series axis by intervals

If the data type of the field displayed on the category/series axis of a chart is of Numeric/String/Date/Time type, you can specify some special function to the field so as to group data on the axis by intervals.

To group data on the category/series axis of a chart by intervals:

  1. In the Display screen of the Chart Wizard, click the Special Function button below the Category/Series box.
  2. In the Special Function dialog, select the special function for the category/series field from the Function drop-down list (for details about the special functions, refer to Specifying special function for group by field), then click OK.
  3. Click Finish in the Chart Wizard to apply the selected special function to the field.
Notes:

Setting Order/Select N condition for category/series field

Sometimes, you may want to show only certain category/series values in a chart and make the values sorted according to a specified order. To achieve this, you can use the Order/Select N feature. By specifying a Order/Select N condition, you can decide how many category/series values will be displayed in a chart and how the values will be sorted. You can also use an Integer-typed parameter to control the value of Select N.

To specify the Order/Select N condition for the category/series field in a chart:

  1. In the Display screen of the Chart Wizard, click the Order/Select N button below the Category/Series box to display the Category/Series Options dialog. See the dialog.

  2. In the Category/Series Order box of dialog, specify the sort order of the category/series values.
  3. Specify the Select condition to All, Top N or Bottom N.
  4. Check the Based On checkbox and specify values for the options that follow.

    If Based On is unchecked, the order for the first or last N values will be based on what you specify in the Category/Series Order box of the dialog; if you check it, the order will be based on values of the summary field and the sort direction you specify via the drop-down list and radio buttons next to Based On.

  5. If you have selected Top N or Bottom N from the Select drop-down list, you can check the Remaining Categories In checkbox and then type a character string in the text field to the right, so that the category/series values beyond the first or last N range will be merged into the group with the name as that character string.
  6. If necessary, check Skip First and input a number M in the text field to the right, then the first M category/series values will be skipped, and the Select N condition will begin with M+1. The skipped values will be merged into the Remaining Categories group.
  7. When done, click OK to accept the settings.
  8. Click Finish in the Chart Wizard to apply the changes.

The following example shows how to control the number of field values that will be displayed on a chart.

  1. In the TutorialReports.cat catalog, create a chart report based on the OrderListbyDate query, select the Clustered Bar 2-D chart type and add the summary Sum_ProductSalesbyProductID to the value axis. The report result looks as follows:

  2. Right-click the chart in the report and select Chart Wizard from the shortcut menu to open the Chart Wizard.
  3. In the Display screen, click the Order/Select N button below the Category box.
  4. In the Category Options dialog, set the Select condition to Top 6, based on Sum_ProductSalesbyProductID descendingly, then check the Remaining Categories In checkbox and input Other into the text field so as to put the categories that do not meet the condition into the Other group. Click the OK button.

  5. Click Finish in the Chart Wizard.
  6. View the report. It now shows as follows:

  7. Back to the Design mode and repeat step 2 and 3.
  8. In the Category Options dialog, check the Skip First checkbox and input 2 in the text field, then click OK.
  9. Click Finish in the Chart Wizard.
  10. View the report again. The result changes as follows: