Graph axis controls

The graph axis settings for each profile graph are fully configurable. To view the settings for a graph axis, click on the associated graph axis button to open the Graph Axis Details dialog. The graph axis settings displayed in the dialog include:

• Minimum and Maximum: The minimum and maximum values determine the magnitude of the domain (x-axis) or the range (y-axis).

• Major and Minor: The graph is subdivided into major (dark grey) and minor (light grey) intervals. The values for the major and minor divisions determine the scale of the graph's major and minor intervals respectively.

• Log axis: The log axis check box determines whether log scales are used for the selected axis when displaying the graph.

• Reverse scale: The reverse scale check box determines whether scaling of the selected axis is reversed or not. If reverse scales are selected, larger values will be shown to the left and smaller values to the right (for the X axis) or larger values will be shown to the bottom and smaller values to the top (for the Y axes).

• Stack graph: for graphs showing more than one property (such as paraffins, naphthenes and aromatics) shades the different profiles and stacks them together for easy visualisation.

The Reset button of the Graph Axis Control dialog resets the graph axis to its default setting removing all custom changes.

The graph axis settings are configured automatically for each axis by default. To determine your own settings, tick or click the relevant check boxes and, if necessary, enter your own values into the adjacent text boxes accordingly. Click Apply to apply your new settings and close the dialog or Close to close the dialog without making any changes.

Stacking graphs

The Stack graph option is only relevant for graphs which display more than one property profile at

the same time, particularly the PNA graph. When the Stack graph option is selected the profiles are

shown stacked on top of each other, rather than crossing, and the area between each profile is

shaded to indicate the relative value of the property at each boiling point. For example, when stacking

the PNA graph the relative amount of paraffin, naphthene and aromatic can be viewed at any boiling

point by comparing the amount of shading for each of the species.

Shading the stacked profiles may cause some computers to run slowly. In this case the shading can be

speeded up by deselecting the Use enhanced graphics option in the Graphing > General Settings

page of the Preferences dialog. See Graphing preferences. Graphs are only shaded if the

Shade stacked graphs option is selected in the Preferences dialog.