2012

Calculating Points
You can use CAL whenever you need to calculate a point or a number within
a command.
For example, you enter (mid+cen)/2 to specify a point halfway between the
midpoint of a line and the center of a circle.
The following example uses CAL as a construction tool. It locates a center
point for a new circle, and then calculates one fifth of the radius of an existing
circle.
Here is the command prompr sequence:
Command: circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 'cal
>> Expression: (mid+cen)/2
>> Select entity for MID snap: Select the notch line (1)
>> Select entity for CEN snap: Select the large circle (2)
Diameter/<Radius>: 'cal
>> Expression: 1/5*rad
>> Select circle, arc or polyline segment for RAD function: Select the large circle
(3)
Calculate Mathematical Expressions in a Dialog Box
You can also enter and evaluate mathematical expressions in a dialog box
using the following format: =expression<Alt+Enter>.
NOTE To evaluate expressions in a dialog box, make sure the system variable,
CALCINPUT, is set to 1.
To start the Command prompt calculator
Do one of the following:
■ At the Command prompt, enter CAL. Then, enter a CAL expression.
■ At a prompt for a command in progress, enter ‘CAL to start the CAL
command transparently. Then, enter a CAL expression to calculate a value
for that prompt.
688 | Chapter 17 Use Precision Tools