The working area of the model editing tool is the editing area. This displays a scale diagram of the current model. The scale can be set using the Map Scale command from the View menu.
Point components (which have no angular extent) are represented as small red crosses which turn cyan when selected. You may drag point components by pressing BSelect when the pointer is inside the area containing the arms of the cross and moving the mouse while keeping the button down.
Optically thin spheres are represented by green circles with magenta borders with a diameter corresponding to the components diameter. The colours are interchanged when the component is selected. You may move a sphere by pressing BSelect with the pointer near the centre of the graphic and moving the mouse while keeping the button down. You can also change its diameter by pressing BSelect when the pointer is over the border of the graphic and moving the mouse while keeping the button down.
Elliptical, Gaussian components are represented by blue ellipses with yellow borders and crossed lines marking the axes of the ellipse. The lengths along the two axes correspond to the full-widths to half maxima of the component. The colours are interchanged when the component is selected. You may move a Gaussian component by pressing BSelect with the pointer near the centre of the component and moving the mouse while keeping the button down. You may also change the length and orientation of an axis of the ellipse by placing the pointer at one end of the axis, pressing BSelect and keeping it down while you move the mouse.
Any component may be selected by clicking on it. This marks the component for modification or deletion using commands from the Edit menu. No more than one component may be selected at any one time. Selecting a component deselects any component that was previously selected. Click on the background to deselect all components.
You may access a pop-up version of the Edit menu by pressing the BMenu button while the cursor is in the editing area.
A reference grid may be displayed in the background of the editing area to provide some guidance in positioning components. You can choose whether this grid is displayed using the Reference Grid toggle and set the spacing between the grid lines using the Grid Spacing command. Both the Reference Grid toggle and the Grid Spacing command are located on the View menu.