Graphs in Gnumeric are created using the Graph Guru. The process involved in using this 'guru' essentially follows the alphabetical labels presented in Figure 10-3.
Advanced users generally start by pre-selecting at least some of the data they will use in their plots. However, this step requires a complete understanding graphs and this step is not described here. Section 10.5 ― Pre-Selecting Data will explain data preselection once the rest of the graphing process has been explained.
The Graph guru can be started in two ways. One way to start the Graph Guru is to click, with the primary mouse button, on the toolbar graph button, . Another way is to select, from the Insert menu, the Chart... menu item. Both approaches will launch the Graph Guru.
The Graph guru opens to the first of two panels. The areas of this panel are shown in the left hand side of Figure 10-3. This panel enables the user to select the type of the first plot in the chart, and its sub-type and style. To make a graph with multiple plots, a user should start by selecting the first plot; subsequent plots can be added later.
The first area, area A, provides a list of the plot types. The user can pick one of the types by placing the mouse pointer on top of that appropriate entry in the list and clicking the primary mouse button. The blue highlight indicates which plot type has been chosen. The characteristics of the different plot types are explained extensively in Section 10.3 ― Plot Types.
The second area of the first panel of the Graph Guru, labeled B in Figure 10-3, presents one or more icons. The icons presented in this area will change depending on what plot type is highlighted in area A. The icons provide a way to select a sub-type of plot, for example, the icons for the column plot type provide the choice between plotting columns of each data series side-by-side or plotting these columns stacked upon each other. These icons may also provide a way to quickly select different styles for the plot type, for example the icons for the line type provide a choice between plotting a simple line or placing markers at the points along the line. The sub-type cannot be changed in the next panel of the Graph Guru without deleting the plot and creating a new one. However, the style choices can be altered in the next panel. The meaning of each of these icons is explained in Section 10.3 ― Plot Types below grouped by plot type. If data has been pre-selected, clicking on the Show Sample will present a preview of the plot type in area B.
Once a plot type has been chosen in area A and an icon selected in area B, the first panel has been completed. Clicking on the Forward button will dismiss the first panel of the Graph Guru and bring up the second panel.
The second panel of the Graph Guru enables users to configure the plot. This includes determining the values which will actually be plotted, adding titles to various components, labels to the data series, names to data categories, and changing the appearance of the different components.
The simplest way both to learn the hierarchy of components in Gnumeric graphs and to understand the properties which can be changed for each component is to work sequentially through all of the components while both noting the components which can be added, listed in the drop down menu when the Add button is pressed, and observing the properties of the component which can be altered, shown in the lower part of the panel, the area labeled J in Figure 10-3. Each component in the hierarchy can be selected in turn using the complete tree of all the components presented in the top leftmost area, labeled F. Components can be selected by placing the mouse pointer over their name in this tree and then clicking with the primary mouse button. The currently selected component is indicated by the blue highlight on that line. Changing the selected component will also change the properties listed in area J. Tree nodes, indicated by arrowheads in front of the name of a component, can be expanded or collapsed with alternative mouse clicks.
The second panel of the Graph Guru only allows two types of actions to be performed: the hierarchy of component elements can be modified or the properties of an element can be altered.
The component elements of the graph can be changed using the buttons in area G. Elements can be added, deleted or re-ordered.
An element can be added by selecting the parent element in the hierarchy presented in area F and then clicking and holding the Add button. This action will reveal a drop down list including all the possible elements that can be added. By moving the mouse pointer onto the drop down list and releasing the mouse button while the pointer is over an element, that element will be added. To add a plot to a chart, it is necessary to navigate into the sub-menu to select the plot type and then into that sub-menu to select a plot sub-type or style in a process that mimics the process of selecting a plot discussed above.
An element can be deleted by selecting the element in the hierarchy presented in area F, and then clicking the Delete button below the hierarchy.
The order of some of the elements can be interchanged using the Order button below the element hierarchy. For example, if an element has two titles, the order of the titles could be swapped. Similarly the vertical order of charts can be interchanged. The effect on plots and series is different. For those elements, the order button changes the stacking order in the front to back dimension. For example, if a chart has a bar plot and a line plot, the order button will change which of the two plots is visible in front of the other.
The bottom area of the second panel, area J in Figure 10-3, allows the user to configure the properties of each element in the hierarchy. When there are many properties, they will be grouped into similar sets and placed on different tabs. The detailed explanation of how to configure each property of each element will be explained in Section 10.4 ― Configuring Graph Element Properties below.
After exiting the Graph Guru, the user must place the graph on a worksheet. Immediately after exiting the Graph Guru, the mouse pointer will have changed to the thin cross-hair cursor. The user can place the graph by moving the pointer over the worksheet and clicking once with the primary mouse button. Alternatively, the user can place and size the graph by determining two of the corners of the graph. This is done by moving the pointer onto the worksheet to the first corner, clicking and holding the primary mouse button, dragging the mouse pointer to the opposite corner and releasing the mouse button.
A graph which has already been created can be modified by clicking on the graph with one of the secondary mouse buttons in order to invoke the context menu and then selecting the Properties menu entry. This will cause the second panel of the Graph Guru to appear which will enable the user to make any desired modifications. The use of the context menu was discussed in Section 9.1.4 ― Invoking the Context Menu for Graphical Elements.
A graph which has been made can be deleted by invoking the context menu and selecting the Delete menu item.