Display

Displays the contents of the queue on the graphical screen:

Format:

SPECTRA> di$*$splay [id]

Description:

If the parameter is omitted, all active queue elements are displayed. Otherwise all queue elements except id are deactivated and id is displayed.

The display function marks the visible queue elements by setting a bit in the GQE header. It keeps track of the number of displayed points (old index) and it also remembers the window limits (old window). That enables SPECTRA to minimize the graphical output, if the display command is not preceded by an erasure of the graphical screen. On-line applications, like scans, make use of this feature by disabling the automatic clear screen. This can also be done from the command line: set inter off.

/ct_ex$*$ternal

Use an external colour table to display ARRAYs. This qualifier is equivalent to setting the symbol use_colour_table.

SPECTRA reads the file GRA_COLOUR_TABLE (environment variable) to fill the colour table before it displays an ARRAY. If the logical does not exist, SPECTRA searches for ONLINE_DIR:COLOUR_TABLE.DAT.

The colours are copied to the colour table of the ARRAY.

See section 10.5 for details about the colour concept.

/au$*$toscale

An autoscale commands preceeds the display. This qualifier is especially useful for commands like display/single/auto name.

/ct_in$*$ternal

The colour table is loaded with the SCANs CT_RED, CT_GREEN and CT_BLUE before ARRAY is displayed. The y-values of these SCANs are in the range [0,255].

The colours are copied to the colour table of the ARRAY.

/ct_ra$*$ndom

/ct_re$*$d

/ct_gree$*$n

/ct_grey

/ct_b$*$lue

The colour table is loaded with these colours before an ARRAY is displayed.

The colours are copied to the colour table of the ARRAY.

/ct_lo$*$ad

Updates the colour table without re-displaying the ARRAY. This makes sense only for PseudoColor visuals.

This qualifier does make sense only, if it is supplied together with /nocls.

/ct_ro$*$tate

Rotates the colour table entries. Can be used with /backwards.

e.g.:

SPECTRA> mandel
Creates a byte map.

SPECTRA> display/ct_random
The colour table is filled with random colours.

SPECTRA> loop "display/nocls/ct_load/ct_rotate; wait 0.1" Rotate the colour table entries. The loop can be stopped by pressing the space bar.

/hold

SPECTRA displays the data and waits for a keystroke before it writes to the alpha screen again (VT330, VT340).

/nocls

No CLS before the data are displayed. Can be used, if one wants to change the colour table only.

/nora$*$ise

The graphic window is not raised by the display command.

/over

Suppresses the clear screen sequence, drawing of the axes and drawing of TEXTs. This is useful for on-line applications in order to have a quick view of the incoming data.

/single

A single slot is displayed in the default viewport without changing the ACTIVATE flags of the GQEs.

/vp

Arrange viewports, Spectra displays the active SCANs in separate viewports.

/zo$*$om

Invokes the interactive zoom feature.

Table 15.2: Zoom options

 

Key	Action
Up/Down-arrow	Increase/decrease the visible range
Left/Right-arrow	Shift the visible range
A	Reset the window limits
S	Reset the window limits and stop