Graphical Function Tab

In the Properties panel, use the Graphical Function tab to define a converter or flow as a graphical function.

To view the Graphical Function tab, click the at the bottom of the Properties panel. For more information about using panels, see Using the Properties Panel.

Note: To view the Graphical Function tab, you have to select a converter or flow.

Graphical

Select the graphical check box to transform the selected converter or flow into a graphical function.

To delete the graphical function relationship from the variable, clear the Graphical check box.

Apply to All

Select the apply to all checkbox to have the same graphical used for all elements of an arrayed variable. This option is only available for a variable that has been defined as an arrayed variable.

If checked, there is only one graphical to edit for all array elements. If unchecked, there will be a dropdown box to select which element of the array to edit the curve for:

The element to edit can also be selected at the bottom of the panel as noted below.

Graph tab

Use the options on the Graph tab to define the graphical function, by drawing a graph of the function.

Grid

This displays the curve for the graphical function.

Tip: You can also edit the input and output values, and so change the curve, by typing new values in the table on the Points tab.

Y-axis minimum and maximum

Specify the Y-axis minimum and maximum values in the two boxes to the left of the graphical function grid. The number in the bottom box (the minimum value) has to be less than the number in the top box (the maximum value).

The values in these boxes set the output range for the graphical function.

Variable name

The name of the variable you're defining the graphical function for appears to the left of the graphical function grid. Here it says "Converter 1", but it will take on the same name as the converter or flow it's defining, which you can type right on the converter or flow.

X-axis minimum and maximum

Specify the X-axis minimum and maximum values in the two boxes beneath the graphical function grid. The number in the box to the left (the minimum value) must be less than the number in the box to the right (the maximum value).

The values in these boxes set the input range for the graphical function.

The minimum value you enter here becomes the first entry in the left column of the table on the Points tab.

The maximum value you enter here becomes the last entry in the left column of the table on the Points tab.

Points tab

Use the table on the Points tab to define the graphical function, by specifying point values for the function.

Tip: You can also edit the output values by dragging the curve in the grid on the Graph tab.

Data Points

Type the number of data points that the graphical function will contain (you have to specify at least two data points). The number you enter here determines the number of points on the graph displayed in the grid on the Graph tab, and the number of rows in the table on the Points tab.

If the graphical function contains more data points than you can easily view on the Graph tab, drag the zoom slider beneath the grid to zoom in and out on the curve. Drag the slider toward the "-" sign to zoom out. Drag the slider toward the "+" sign to zoom in.

If a graphical function contains more data points than you can see at once in the table on the Points tab, scroll bars will appear so you can scroll up and down the table list.

Graph Type

Click the appropriate button to select the type of graph you want to use for the graphical function. The type you select affects the appearance of the graph on the Graphical Function tab. It also tells the software how to calculate values in the function that aren't specified by the data points (that is, how to calculate values that are off the graph):

The following picture shows the difference between the same curve graphed as a continuous and as a step graph.

When you select discrete, there will be an option to treat the stepwise value as accumulated:

When Accumulated is checked, each discrete value will be used to determine an area and interpolated output with the same area will be generated. For example

Accumulated is useful when you are trying to match totals for one period of time but still having the values between those times change slowly.

Note For time based graphicals using TIME+DT/2 instead of just TIME will give the most precise value for the area under the accumulated curve.

Preset Shapes

There are a number of preset shapes available to simplify the process of creating a smooth graphical relationship. Rather than typing in points or drawing the initial shape, you can start from one of the different presets.

Select one of the line shapes by clicking on the shape in the panel. The graph points will be replaced with those of the shape. After clicking (except for the linear shapes) a slider will become visible allowing you to set curvature:

Drag the slider to increase or decrease the curvature which varies from 0.1 to 10. As you move the slider the points or graph will change. When you are satisfied with the shape click on Done.

After you finish adjusting curvature you can edit the graph or points as described above.

Apply To All Element Selection

For more information about defining graphical functions for arrayed variables, see Creating a Graphical Function.

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