6
Creating graphs in Discoverer

Creating graphs in Discoverer

This chapter explains how to create graphs in Discoverer to answer typical business questions, and contains the following topics:

• "What is a Discoverer graph?"

• "About using graphs in Discoverer"

• "More about worksheets and graphs"

• "About saving Discoverer graphs"

• "About setting font options"

• "About components of a Discoverer graph"

• "About graph types and sub-types"

• "About graph types available in Discoverer"

• "Notes about creating bubble graphs"

• "Notes about creating high-low-close stock graphs"

• "Notes about creating dual-Y charts"

• "Notes about creating pie graphs"

• "How to create a graph"

• "How to edit a graph"

• "How to change the position of a graph on screen"

• "How to delete a graph"

What is a Discoverer graph?

A Discoverer graph is a pictorial representation of worksheet data. For example, you might create a graph to enable you to easily analyze trends in your data.

About using graphs in Discoverer

Discoverer provides a wide range of graphs to help you analyze data visually (e.g. area, bar, line, and scatter graph). For a complete list of graph types available in Discoverer, see "About graph types available in Discoverer".

Discoverer provides the Graph Wizard to help you create and edit graphs (see figure below).

Figure 6-1 Discoverer Graph Wizard

Text description of the illustration gw.gif

The Graph Wizard helps you:

• choose a graph type

• choose the data that you want to represent in a graph

• specify how the graph will look

If you change the data displayed in a worksheet, the graph automatically updates to show the new data.

Once you have created a graph, you can also edit areas of a graph using the Graph toolbar and drop down menus (for more information, see "How to edit a graph").

More about worksheets and graphs

In Discoverer, you create a graph for the items currently displayed on a worksheet. Before you create a graph, make sure that you display the numeric worksheet values that you want to plot on the graph.

Each Discoverer worksheet can have one graph. If you already have a graph in a worksheet and want to create a completely new graph, delete the existing graph (see "How to delete a graph"), then create a new graph (see "How to create a graph").

Alternatively, you can also existing edit graphs (see "How to edit a graph").

Notes:

• To edit a Discoverer graph, you must use the same Discoverer tool that you used to create the graph. In other words:
  • if you created a graph using Discoverer Plus, you must use Discoverer Plus to edit the graph

  • if you created a graph using Discoverer Desktop, you must use Discoverer Desktop to edit or view the graph

• Graphs created in Discoverer Plus can be viewed in Discoverer Plus, Discoverer Viewer, and Discoverer portlets.

• Graphs created in Discoverer Desktop can only be viewed in Discoverer Desktop.

• A worksheet can have both a Discoverer Plus graph and a Discoverer Desktop graph saved with the worksheet.

About saving Discoverer graphs

When you save a workbook, Discoverer saves graphs automatically for you as part of the worksheets in the workbook. In other words, you do not have to explicitly save graphs. Any changes you make to the graph are also saved automatically when you save the workbook.

About setting font options

Each page of the Graph Wizard enables you to change the default font options for various graph components. For example, the X-axis title, the X-axis label, and the legend font. You use the "Graph Wizard dialog: Font dialog tab" to set the font style.

The figure below shows how the Title Font button on the "Graph Wizard dialog: Titles, Totals, and Series tab" is used to display the "Graph Wizard dialog: Font dialog tab".

Figure 6-2 The Graph Wizard font dialog

Text description of the illustration gfont.gif

The "Graph Wizard dialog: Font dialog tab" enables you to change the default font styles (e.g. font, font size, font color).

About components of a Discoverer graph

Discoverer gives you great flexibility when producing graphs, enabling you to configure every component of a graph. The figure below shows the typical components of a Discoverer graph.

Figure 6-3 Components of a Discoverer graph

Text description of the illustration gw-graph.gif

Key to figure:

1. The graph title.

2. The Y-axis label.

3. The plot area, showing worksheet data represented on the graph.

4. The X-axis label.

5. Tick label.

6. The graph legend.

7. A reference line, used to emphasize particular data values on a graph.

About graph types and sub-types

To present your worksheet data visually in Discoverer, you can choose from a wide range of graph types. For example:

• bar graph

• line graph

• pie graph

Each graph type has one or more variations, or sub-types. For example, the sub-types for the Bar graph type include the following:

• Bar

• Dual-Y Bar

• Percent

Most graph sub-types have a three-dimensional effect that you can switch on and off as required (using the 3D-Effect check box).

Note: 3D-Effect should not be confused with three-dimensional graphs, such as 3D-Cube and Surface, which are used to represent multi-dimensional data.

Some graphs also have dual-Y sub-types, which have two Y-axes. Dual-Y graphs are useful for showing the following types of data:

• data of different measures (such as region sales on the Y1-axis and profit on the Y2-axis)

• data of different scales (such as sales on the Y1-axis and percent of total sales on the Y2-axis)

About graph types available in Discoverer

The table below shows the graph types that are available in Discoverer.

Graph icon	Graph name and description
Text description of the illustration s_area_v.gif	Area graph - shows trends or changes in data using filled-in areas.
Text description of the illustration s_bar_ve.gif	Bar graph - compares values using vertical bars. Each value is represented by a single bar. Bar graphs shows variation over a period of time or illustrates comparisons between values. The stacked sub-type shows each value's relationship to a whole. Bar graphs can have two Y axes (for more information, see "Notes about creating dual-Y charts").
Text description of the illustration s_circle.gif	Circular graph - shows directional data and cyclical patterns in data.
Text description of the illustration s_comb.gif	Combination graph - combines bars, lines, and areas.
Text description of the illustration s_bar_ho.gif	Horizontal Bar graph - compares values using horizontal bars. This graph type is identical to a bar graph except that the bars lie horizontally, rather than standing vertically. The stacked sub-type shows each value's relationship to a whole. Bar graphs can have two Y axes (for more information, see "Notes about creating dual-Y charts").
Text description of the illustration s_line_v.gif	Line graph - shows trends or changes in data at even intervals. Data is represented as a line that connects a series of data points.
Text description of the illustration s_pareto.gif	Pareto graph - shows trends across groups periodically and cumulatively. Each group is displayed as a column. A plotted line also shows the cumulative value across groups.
Text description of the illustration s_pie.gif	Pie graph - shows data as sections of a circle, similar to slices of a pie. A pie graph shows the proportion of parts to the whole. It is useful for emphasizing a significant element, such as the highest value. Note that a pie graph displays only one row or one column of data at a time (for more information, see "Notes about creating pie graphs").
Text description of the illustration s_scatte.gif	Scatter/Bubble graph Scatter graph - displays data as points scattered over the plot area. Each point is a value whose coordinates are specified by two numeric measures. A scatter graph is useful for showing relationships between two measures, for example Sales and Cost. All points are the same size, regardless of their value. Bubble graph - shows data in a similar way to a scatter graph, but with an extra dimension that uses the size of the bubbles. Each bubble is a value whose coordinates are specified by three numeric measures. A bubble graph is useful for comparing data that has three measures (for more information, see "Notes about creating bubble graphs").
Text description of the illustration s_stock_.gif	Stock graph - shows highest stock price, lowest stock price, and closing stock price as bands on a time axis. Stock graphs are useful for comparing the prices of different stocks or the stock price of an individual stock over time (for more information, see "Notes about creating high-low-close stock graphs").
Text description of the illustration s_threed.gif	ThreeD graph - shows three-dimensional (ThreeD) data in a true three-dimensional graph, where you have an X axis, a Y axis, and a Z axis. 3D graphs have a floor, a wall, and a background. There are four 3D graph sub-types: 3D Bar, 3D Cube, 3D Area, and 3D Surface. 3D graphs are useful for showing trends or to compare values along two dimensions. Note: This graph type is not the same as a two dimensional graph with the 3D Effect turned on. The 3D Effect simply adds depth to any graph type.

Notes about creating bubble graphs

To create meaningful graphs in Discoverer, you need to have the correct worksheet configuration for the style of graph that you want to use.

When you create bubble graphs, follow these guidelines:

• You need at least three items per bubble:
  • the X item - the bubble's location on the X-axis

  • the Y item - the bubble's location on the Y-axis

  • the Z item - the size of the bubble (in positive numbers)

The figure below shows an example Discoverer worksheet and the worksheet data plotted on a bubble graph.

Figure 6-4 Example Discoverer worksheet and bubble graph

Text description of the illustration gr_bub.gif

For example, you might have the following items on a bubble graph (see figure above):

• store size as the X item (the 'Store size m2' item on the worksheet)

• advertising costs as the Y item (the 'Advertising $' item on the worksheet)

• sales as the Z item (the 'Sales $' item on the worksheet)

You could then see whether the largest stores with the most advertising generated the highest sales revenue.

The figure above shows how worksheet data is represented on a bubble graph. The bubbles represent Sales. A large bubble represents large sales revenue. A small bubble represents small sales revenue.

Notes about creating high-low-close stock graphs

When you create high-low-close stock graphs (sometimes known as stock charts), follow these guidelines:

• You need at least three items in the following order:
  • high price

  • low price

  • closing price

    Figure 6-5 Example worksheet and high-low-close stock graph

    
    
    Text description of the illustration gr_stock.gif

  For example, the figure above shows a worksheet configuration for charting a stock price over time (January, February and March). The worksheet data is arranged 'Series by row'.

• Stock values for high, low, and closing prices must appear on the same row or column series as groups of three.

• To display high, low, and closing prices for more than one period, the data must be in multiples of three. For example, three columns for period one, three columns for period two, and so on.

• If a high-low-close stock graph contains more than stock, and prices overlap, some stock values will obscure other stock values.

Notes about creating dual-Y charts

When you create dual-Y graphs, follow these guidelines:

• You can use the dual-Y facility with the following types of graph:
  • bar

  • line

  • area

The figure below shows an example dual-Y bar graph with a Y axis for sales and a second Y axis for costs.

Figure 6-6 Example worksheet and dual Y graph

Text description of the illustration gr_dualy.gif

• Dual-Y graphs require at least two items.

• By default, the series are displayed in the following way:
  • series one is displayed on the Y1 axis

  • series two is displayed on the Y2 axis

  • all subsequent series are displayed on the Y1 axis

In the figure above, the Y1 axis represents sales on the scale 0 to 1 million. The Y2 axis represents costs on the scale 0 to 50,000. You can therefore analyze sales and costs side by side even though they use different scales.

Notes about creating pie graphs

When you create a Pie graph (sometimes called a Pie chart), you choose which row or column you want to represent. The figure below shows how a row of data is represented on a pie graph.

Figure 6-7 Using a worksheet row to create a pie graph

Text description of the illustration pie3.gif

The figure below shows how a column of data is represented on a pie graph.

Figure 6-8 Using a worksheet column to create a pie graph

Text description of the illustration pie2.gif

How to create a graph

You create a new graph for a worksheet when you want to display data and trends visually. Discoverer provides the Graph Wizard to help you create a graph of your worksheet data. If at any time you want to use default settings for the remaining steps in the Graph Wizard, simply click the Finish button.

Hint: Before you start, make sure that the worksheet displays the data that you want to plot on the graph.

To create a graph:

1. Choose Graph | New Graph to display the "Graph Wizard dialog: Graph Type tab", and choose a graph style from the list of graph types and graph sub-types.

   
   
   Text description of the illustration graph_1.gif

   Note: If the Graph | New Graph option is not available, the worksheet already has a graph (which might be hidden). If you want to create a new graph, do one of the following:

   • click Graph | Delete Graph to delete the existing graph, then click Graph | New Graph to create a new graph

   • click Graph | Edit Graph to display the Graph Wizard, then change the existing graph to the style you want

   For more information about choosing a graph type, see "About graph types available in Discoverer".

2. Click Next to display the "Graph Wizard dialog: Titles, Totals, and Series tab", where you:
   • (optional) define a graph title

   • use the What would you like to display? options to select what data you want to display (i.e. data only, totals only, or both data and totals)

   • use the Graph series by options to select whether to plot data by row or column

   • (optional) when creating a pie graph, you select which row or column you want to plot on the graph

     
     
     Text description of the illustration graph_2.gif

   If you are creating a pie graph, the Pie Chart Options button is active.

3. (optional) To select which column or row to plot on the graph:
   1. Click Pie Chart Options to display the "Graph Wizard dialog: Pie Chart Options tab (column)" or "Graph Wizard dialog: Pie Chart Options tab (row)".

   2. Select the row or column that you want to graph from the list of items.

   3. Click OK.

   Note: When you click Next, you go straight to the "Graph Wizard dialog: Plot Area tab". This is because you do not define X or Y axes for pie graphs.

4. Click Next to display the "Graph Wizard dialog: X-Axis tab", where you specify how the X axis is displayed.

   
   
   Text description of the illustration grphxaxs.gif

5. Click Next to display the "Graph Wizard dialog: Y-Axis tab", where you specify how the Y axis is displayed.

   
   
   Text description of the illustration grphyaxs.gif

6. (optional) If you are creating a dual-Y graph, click next to display the "Graph Wizard dialog: Y2-Axis tab", where you specify how the Y axis is displayed.

   For more information about creating dual-Y graphs, see "Notes about creating dual-Y charts".

7. Click next to display the "Graph Wizard dialog: Plot Area tab", where you specify the color and style of plotted data.

   
   
   Text description of the illustration grphplot.gif

8. Click Next to display the "Graph Wizard dialog: Legend tab", where you specify the graph legend that provides information about how items are represented on the graph.

   
   
   Text description of the illustration grphlgnd.gif

9. Click the Finish button to save the details and display the graph.

Discoverer displays the graph on the worksheet.

Text description of the illustration grph.gif

Notes

• To automatically arrange graph components, right-click on the graph to display graph menu options, then choose Auto Layout.

• By default, graphs are displayed at the right-hand side of worksheet data. To change where a graph is displayed, choose Graph | Display Graph and choose a position from the list of options.

• For information about positioning graphs, see "How to change the position of a graph on screen".

How to edit a graph

You edit a graph to change how it is displayed on a worksheet. For example, you might want to change the graph type, change the axis labels, or change the color of plotted items.

Note: If you want to change which items are displayed on a graph, you need to change which items are displayed on the worksheet. To do this, click Sheet | Edit Sheet to display the "Edit Worksheet dialog", then display the "Edit Worksheet dialog: Select Items tab".

To edit a graph:

1. Display the worksheet that contains the graph.

2. Edit the graph using any of the following methods:
   • Choose Graph | Edit Graph to display the "Graph Wizard dialog: Graph Type tab". You can click the tabs along the top of the dialog to do directly to the area that you want to edit.

   • Select the area of the graph that you want to edit, and use options on the graph menu bar to manipulate the graph area (for more information, see Section , "About the Discoverer menu bar and toolbars").

   • Select the area of the graph that you want to edit, right-click to display graph menu options for that area, and use the graph menu options to manipulate the graph area.

     Hint: To automatically arrange the graph components, right-click to display graph menu options, then choose Auto Layout.

3. Click OK to save changes and close the Graph Wizard dialog.

Discoverer updates the graph as specified.

Notes

• To see changes take effect immediately, click Apply at any time. The graph is updated within the Discoverer worksheet area.

How to change the position of a graph on screen

You change a graph's position on screen when you want to change where it is displayed in relation to the worksheet data. For example, you might want to display a graph below worksheet data, or display a graph in a separate window.

To position a graph:

1. Choose Graph | Display Graph and choose one of the following menu options:
   • Separate Window - display the graph in a window that floats above the worksheet window. You can move the graph window to any location on your screen by dragging it with the mouse.

     Note: If you close the separate window, choose Graph | Display Graph and choose a display option to re-display the graph.

   • Right of Data - display the graph on the right of the worksheet.

   • Left of Data - display the graph on the left of the worksheet.

   • Above Data - display the graph above the worksheet.

   • Below Data - display the graph below the worksheet.

   • Hide/Unhide Graph - display the graph or hide the graph. The Hide option does not delete the graph.

   Discoverer displays the graph in the position that you specified.

Notes

• When you choose Graph | Display Graph and choose a position from the list of options, you change how the graph is positioned on screen. This does not affect how a worksheet and graph print out. For example, Discoverer always prints graphs on a separate page, after the worksheet data.

• If you use Discoverer Viewer or OracleAS Portal to publish worksheets, Discoverer Viewer and OracleAS Portal display worksheet graphs above or below worksheet data.

• For information about how to delete a graph permanently from a worksheet, see "How to delete a graph".

• By default, the graph is sized to fit inside the graph window. To disable the autolayout option, choose Graph | Fit to window, and clear the check box.

• To automatically arrange the graph components, right-click to display graph menu options, then choose 'Auto Layout'.

How to delete a graph

You delete a graph when you no longer want to use it, and will not require the graph later. For example, you might want to delete a temporary graph that you created to produce a printed report.

To delete a graph:

1. Choose Graph | Delete Graph.

   A warning message appears.

2. Click Yes to delete the graph.

   The graph is removed from the worksheet.

Notes

• If you want to remove a graph without deleting it, choose the Graph | Display Graph | Hide Graph option. You can then display the graph later if required.