Annotations

Command DRAW  can be used to annotate a plot. The basic operations performed by command DRAW are :

• DRAW TEXT Xpos Ypos "Text" Centering
    to draw a text at position (Xpos,Ypos) (in current units) with the specified centering code. This command works more or less like the GreG command of same name. Please refer to the GreG manual for details. In particular, you can include Greek letters and Symbols in the text using the escape character . A strange thing may appear on the screen, but it is O.K. on the plot. If you have doubts, use ZOOM REFRESH before command HARDCOPY to see exactly what your plot looks like.
• DRAW UPPER Xpos "Text"
    to draw a vertically oriented text at position Xpos, with a vertical line connecting the beginning of the text to the current spectrum. This text and line are written at position Xpos, in units of the upper axis. Typically, this command is used to mark spectral line identifications.
• DRAW LOWER Xpos "Text"
    same as above, but with Xpos in units of the lower axis.
• DRAW WINDOW [Level]
    shows the current windows by marks on the graphic plot. Level is an optional arguments indicating at what Y value the marker should be put (Default 0).
• DRAW MASK [Level]
    same as above but for the current masks.
• DRAW KILL [Channel]
    kills the specified channel (current one if using the cursor) by attributing it the ``blanking'' or ``undefined'' value.
• DRAW FILL [Channel]
    Fills the specified channel (current one if using the cursor) by interpolation between the nearest non-blanked channels. The channel must have been killed before.

Any other character will not draw anything, but simply returns the cursor position, with corresponding values of the velocity, frequency, image frequency, channel number.