Define points with the Input grapher

When using the Input grapher, you use points to define the sectors of the curve .

Add and delete points

Each sector of the graph is defined by two points.

To add a point:

• Double-click the appropriate position in the graph, or right-click at the appropriate position, and then select Add Point.

You can look at the cursor position, indicated above the graph region , to create a point in a particular place. When a new point is created, the curve sector between it and the preceding point becomes active (highlighted in yellow).

To delete a point:

1. Position the cursor over the point.

   The cursor becomes a white hand, and the point turns red.

2. Right-click and select Remove Point from the context menu.

   The software removes the point, and the point immediately to the right closes the sector. If you remove the ending point of a curve, the point immediately to the left ends the curve.

   Note: Immediately after you delete a point, the software recomputes the remaining points to assure the continuity of the law.

Reposition a point or group of points

To move a point vertically or horizontally in a straight line:

1. Press and hold the Shift key.
2. Use the mouse to drag the point as described previously.

   The origin of the dotted lines drawn in black is the initial position of the point. It can move on these two axes.

To reposition a point on a curve:

1. Position the cursor over the point.

   The cursor becomes a white hand, and the point turns red.

2. Click and drag the point to the new location while holding down the left mouse button.

   The cursor becomes a black hand, and the coordinates of the cursor appear above the graph region.

   The point moves to the new position, moving the part of the curve to the right of the point as well. When you move point X _i+1 , point X _i remains fixed. You cannot move X _i+1 to the left of Xi (a sector cannot have a 0 or a negative area). The characteristics of the sector made up of points X _i+1 and X _i+2 and all sectors to the right are recomputed in function of the new coordinates of X _i+1 .

   If you want to move only one point, without affecting the other points on the curve, lock the point immediately to the right.

3. When the point is in the appropriate location, release the mouse button.

   To the right of the cursor position, the letters PS (point selected) indicate the movement of the point.

Lock and unlock points

To lock a point:

1. Position the cursor over the point.

   The cursor becomes a white hand, and the point turns red.

2. Right-click and select Lock Point from the context menu.

   An anchor symbol indicates a locked point.

   When a point is locked, the points that follow are also locked.

If point X _i+3 is locked and the user moves X _i+1 , the sector X _i+1 - X _i+2 is considered semi-locked. The characteristics (slope) are fixed and recomputed in function of X _i+1 . It is the sector X _i+2 - X _i+3 that is changed.

Note: To temporarily lock the preceding and following points, hold down the Ctrl key while moving a point.

To unlock a point:

1. Position the cursor over the point.

   The cursor becomes a white hand, and the point turns red.

2. Right-click and select Unlock Point from the context menu.

Show Me how to create and edit a curve in the Input Grapher