Source editor: Symbols section

In the Symbols section, you can define named, auxiliary quantities for use in the selected source's output channels and (if combined with the source's identifier) throughout the Chart.

This allows source definitions to be broken up in computational elements with well-defined purposes and descriptive names, while keeping the Output section clean. Ideally, the latter should only contain references to Symbols.

Each row in the symbol table is a record consisting of a Symbol name, a Definition and an optional Comment:

Symbol names declared here can be used in references throughout the source. They should be unique within the source and follow the usual symbol naming conventions.

In the screenshot above, the definition of the symbol _bol contains references to the built-in symbols SELF, FROM_DATE and TO_DATE; and to the parameters (see below) _ndays and _sigma. The definitions of the symbols _hibol and _lobol in turn contain references to _bol. If you wanted to plot Bollinger bands, you could put the symbols _hibol and _lobol in two of the source's output channels.

Symbols can also be referenced outside the source where they are defined (in other sources and in the Chart's captions). To do so, use a dot to combine the source's identifier with the symbol. For instance, the symbol _lobol in the source _bol would be referenced as _bol._lobol. Use the built-in identifier grid to access field values (for the selected record) in the view's Grid object, as in grid._nav.

Be sure to avoid name clashes with the Chart's Parameters and built-in symbols.

Each Definition is an expression which evaluates to a number (float) or to an array. It's recomputed automatically as needed in the course of source evaluation.

If the symbol's value is a constant (i.e. no expression is required to define it) consider using a Parameter instead. Doing so is more efficient and allows the value to be modified on the fly from the Chart parameter window without having to open the source editor.

The Comment can be any text; it has no effect on symbol evaluation.

Symbol table entries can be added, copied, moved and deleted using the table's pop-up menu or the equivalent buttons in the window's upper right corner:

	Edit as text. Opens a window with an alternate representation of the symbol table: plain text (no cells) with field columns separated by tab characters. Quicker to edit than the regular spreadsheet-style form when dealing with large definitions and/or long expressions, and particularly handy when you need to transfer a whole section of a symbol table (just copy and paste).
	New. Click to add an empty row to the symbol table. If a row is selected in the table, the new row will be inserted below the selected row, otherwise it will be added at the bottom of the table.
	Copy. Click to add a copy of the selected row to the symbol table. The new row is inserted below the original.
	Delete. Click to delete the selected row.
	Move up. Click to move the selected row toward the top of the symbol table.
	Move down. Click to move the selected row toward the bottom of the symbol table.