Investment Studio > Setup > Graph > Source editor

All the data displayed in a Graph object is produced by expressions and settings collectively known as the Graph's (data) sources. Click Data > Sources in the Graph's pop-up menu to open the Graph's source editor.

Overview

The panel at the top of the source editor

is used to specify the range (FROM_X, TO_X) and number of discrete STEPS in the Graph's independent variable (X). All fields in this panel can be either constants or full-fledged expressions, as long as they evaluate to numerical results satisfying FROM_X <= TO_X and STEPS > 0.

Since FROM_X, TO_X and STEPS are not associated with any particular source, it's necessary to qualify the names of Symbols and Parameters used in such expressions with the identifier of the source where they are defined. In the screenshot above, the parameters _HALF_WIDTH and _SDEV are qualified with the source identifier _DISTRIBUTION.

Below the X panel are three tabbed sections: Output, Symbols and Parameters.

All the Graph's data sources are listed in the Output section's source table:

  Sources can be added, moved and deleted using the Output section's toolbar or the source table's pop-up menu.

Each data source has its own output channels, symbols and parameters (see below). An entry must be selected in the source table for the output channel panel, the Symbols section and the Parameters section to be enabled.

When the Favorites button in the Output section's toolbar is depressed, a list of available favorite sources is displayed to the left of the source table:

How the selected source sends data to the Graph is determined by the output channel expressions listed below the source table:

The symbol NXS in the screenshot above is one of several built-in symbols available to Graph expressions.
In principle, all output channel entries (see above) can be full-fledged expressions. In practice, this can make them hard to read and to modify, and there are limits to what can be done with a single expression. It is therefore often preferable to break down graph sources in multiple, named building blocks and then use references to them in the Output section.

The Symbols section is where such building blocks are defined. Each one must be labeled with a Symbol (unique within the source) and must contain an expression (Definition) which evaluates to a numerical result or to an array:

  The symbols STEPS, FROM_X, TO_X in the screenshot above are defined in the source editor's top panel; the symbols SELF, FROM_DATE and TO_DATE are three of several built-in symbols available to Graph expressions.
Parameters are a special kind of symbols. Like other symbols, they can be referenced in expressions throughout their source (or throughout the Graph, when combined with the source's identifier) but they are not themselves defined using expressions. Instead, each parameter has a constant float Value, which is specified explicitly in the Parameters table:

  The other columns in the Parameters table determine if and how each parameter will show up in the Graph parameters window (opened by clicking Sliders in the Graph's pop-up menu).

Nothing you do in the source editor will affect the Graph object until you click Apply (apply changes and keep editing) or OK (apply changes and close editor). If you make some changes and then decide to discard them, close the source editor by clicking the button in its upper right corner. This causes all changes made since the last Apply to be discarded.