The CLEAR command

Because of the multi-window and directory capabilities, the CLEAR  command has many possible arguments.

• CLEAR ALPHA erases the alphanumeric screen alone, without affecting the plot. If possible, rather than erasing the alpha screen, the graphic screen (current window) is raised up.

• CLEAR DIRECTORY [DirName] makes the named directory (or by default the current directory) invisible. All the attached structure becomes invisible. The Graphic screen is not updated, use command ZOOM REFRESH to do it.

• CLEAR GRAPHIC lowers the graphic windows, popping up the alpha screen.

• CLEAR PLOT is equivalent to either CLEAR TREE or CLEAR WHOLE, depending on user preference as expressed in command CHANGE CLEAR .
• CLEAR SEGMENT destroys the last graphic segment, i.e. the part of the plot corresponding to the last graphic command. Can be used repetitively. The Graphic screen is not updated, use command ZOOM REFRESH to do it.

• CLEAR SEGMENT SegName makes the named segment invisible. The Graphic screen is not updated, use command ZOOM REFRESH to do it. This is equivalent to CHANGE VISIBILITY NameSeg OFF.

• CLEAR TREE deletes the current directory, that is all subdirectories descending from the current main directory. Other parallel trees (if any) are not destroyed.

• CLEAR WHOLE deletes the whole plot, all main directories and their subdirectories. A new (empty) main directory is automatically recreated with one associated window.

• CLEAR WINDOW delete the current graphic window. Beware that this may leave the plot with no associated window.