Cursor

Invokes the software cursor.

Format:

SPECTRA> cur$*$sor [id1] [id2]

Description:

The software cursor allows you to look at your data points in detail, change the y-values of the points or set markers which can be used in subsequent operations.

When the cursor function is exited, the current cursor position is stored in the symbol CURSOR_X and CURSOR_Y.

While the cursor is moved through a SCAN, SPECTRA displays the current position (x and y), (x - x0) and markers. x0 can be set with the 'P' key to any point inside the SCAN. The (x - x0) feature has been implemented for rough estimates of peak widths: Move the cursor to the peak, press 'P' and move the cursor to the 50% level. (x - x0) is about half of FWHM.

The table 15.3.17 lists the options you have when the cursor is enabled. "1..0" means: Pressing "1" sets the cursor to the first point of the SCAN, "0" to the last and the other numbers put it somewhere in between. The right- and left-arrow are used to start or stop the motion of the cursor through the data points. There is an acceleration of the cursor speed. The up- and down-arrow sets the cursor to the last and first data point.

If no parameter is supplied, the cursor is called for the first SCAN. If two parameters are present, a second SCAN is superimposed.

/keep_viewport

The cursor routine displays the scan in the default viewport, since it is very likely that the user wants to see the data as big as possible for the cursor operations. The qualifier /keep_viewport directs SPECTRA to keep the actual viewport.

/layout

SPECTRA uses the graphical attributes from the LAYOUT in the slot of id1 or in slot 0.

/nodisplay

The drawing of the SCAN is suppressed. This option can only be selected, if the scan has been displayed before.

Table 15.1: Cursor options

 

Key	Action
1..0	Cursor left..right
$\leftarrow \rightarrow \uparrow \downarrow$	Move left/right fine/coarse
-	Goto next marker
A	Autoscale and display
C	Change y-value of the current point
D	Redisplay scan
E	Delete the current point
H	Help
I	Delete the points between the markers
l/L/r/R	Move a small/big step left/right
M/N	Store/remove marker
O	Restore original window
P	Set x0
S	Stop cursor
V	Display values/toggle
Y	Stores the current point in the file marker.lis
Z	Zoom (requires two markers)