Some keys are active and serve as shortcuts for different commands in the pop-up menu.

If the User clicks with this button on any point the plot highlights it, shows the name of the object or variable associated and the values of the X and Y variables in this particular plot. To remove this information from the screen click out of the boundaries of the plot (out of the red box)

When the User press the right mouse button, a pop-up menu appears on the window:

• set symbol

  

  The values in 2D plots can be represented by:

  point	a tiny filled point.
  circle	a tiny open circle.
  square	a tiny open square (default).
  number	for variables: the number as defined in the data file. for objects: the number as defined in the data file.
  name (N)	for variables: the sequential index of the variables. for objects: the name as defined in the data file. The same effect is obtained pressing the N key when the cursor is over this window.
  size	it is used to select the symbol size. Any real number between 0.0 and 4.0 can be used. Size modifications are only allowed for circle and square symbols

• symbol color

  

  This option appears in the pop-up menu only when:

  1. The plot is an object plot (the symbols represent objects)

  2. The User has defined object types or a spectrum (see File->Object type commands).

  In this case, this command allows the user to alternate between the color scheme given by the type of objects (the default) and by the spectrum.

• label axis

  

  Allows the User to include text in the plot. The text can be introduced in four different positions: horizontal-top, horizontal-bottom, vertical-left and vertical-right. The User is prompted to enter a string in a small box at the bottom of the window. When the User press the <Enter> key, the string is displayed in the selected position.

• output

  

  VolSurf can save the contents of 2D plots in three formats: RGB bitmaps, PostScript files and XY ASCII files.

  RGB (only for IRIX)	Saves the contents of the window in IRIS RGB format.
  PostScript	Saves the contents of the windows in PostScript format.
  XY	Saves the data represented in the window in a plain text (ASCII) file. The data in this file is organized in a table which contains three columns separated by tabulation marks; the first column represents the horizontal coordinates of each point plotted, the second represents the vertical coordinates of each point plotted and the third contains the name of the objects between double quotes.

  In all three options, the User is prompted to enter the file name in a small box in the bottom of the window.

• visualization style

  

  This menu contains different options to customize the way the plot is represented in the screen.

  line smoothing	The options are ON and OFF. When it is ON, VolSurf uses antialiasing techniques to render smoother lines in the screen. In plots containing a large number of points this option can increase the time required to update the display.
  symbol font	The options are SMALL and LARGE. This option defined the font used by VolSurf to render in the screen the names and numbers of the points.
  monochrome	The options are ON and OFF. When it is ON, the plot is rendered in black and white.
  background	The options are BLACK and WHITE. Changes the background of the plot. The foreground colors change accordingly to keep visible all the objects in the screen.
  show structure	3D structures can be visualised by setting to ON this option. Click on the objects of the 2D plots to visualise their 3D structures.
  show confidence	The three confidence lines can be visualised setting ON this option. See below about the confidence level.

• find object

  

  This command allows to locate and highlight an object of the plot. The search can be made by name or by number. When by name is selected the User must specify the name in the command line. The name can also be approximate, letting VolSurf decide which is the closest name to the one specified.

• confidence level

  This command allows to set the confidence interval (shown as three coloured lines) in the 2D-PLS scores plot.

  The Central value, Distance grey field must be filled with two values, separated with a comma. Type the "central value" of Y where move the yellow line and the "distance" to set the interval of the blue and red bars. Decimal digits need the point. For example typing 0, 0.5 the yellow line will separate the plot in two regions: one with the compounds with activity greater than zero and the other with activity smaller than of zero, while the blue and red lines define an activity interval of 0.5 around the central position.

  Note: to hide (or show) the three confidence lines, activate the pop-up menu with the right mouse button, select visualization style and then show confidence OFF (or ON).

• exit (X)

  Closes the window and exits from the 2D plot application. The same effect is obtained pressing the X key when the cursor is over this window.