characters), as might have been left on the stack by entries when running in algebraic mode, will be ignored.

Access:

!Î

 

( Îis the left-shift of the `key).

Input/Output:

 

 

 

 

 

 

 

 

 

 

Level 1/Argument 1

Level 1/Item 1

 

 

 

 

 

 

 

n

→

objn

 

 

 

 

 

See also:

LAST, LASTARG, PICK

 

 

 

 

 

 

 

APPLY

Function

 

 

Type:

 

 

Description:

Apply to Arguments Function: Creates an expression from the specified function name and

 

arguments.

 

 

A user-defined function f that checks its arguments for special cases often can’t determine whether a symbolic argument x represents one of the special cases. The function f can use APPLY to create a new expression f(x). If the user now evaluates f(x), x is evaluated before f, so the argument to f will be the result obtained by evaluating x.

When evaluated in an algebraic expression, APPLY evaluates the arguments (to resolve local names in user-defined functions) before creating the new object.

Access: …µAPPLY

Input/Output:

Level 2/Argument 1 Level 1/Argument 2Level 1/Item 1

 

1

n

}

'name'

→

1

n

 

 

{ symb

... symb

 

'name(symb

... symb )'

Example:

The following user-defined function Asin is a variant of the built-in function ASIN. Asin checks for

 

special numerical arguments. If the argument on the stack is symbolic (the second case in the case

 

structure), Asin uses APPLY to return the expression 'Asin(argument)'.

 

 

« → argument « CASE -3 FS? THEN argument ASIN END

 

{ 6 7 9 } argument TYPE POS THEN

 

 

 

'APPLY(Asin,argument)' EVAL END

 

 

 

'argument==1' THEN 'π/2' END

 

 

 

 

'argument==-1' THEN '-π/2' END

 

 

 

argument ASIN

 

 

 

 

 

 

END » »

 

 

 

 

 

 

 

`OAsinK

 

 

 

 

 

 

See also:

QUOTE,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ARC

Command

 

 

 

 

 

 

Type:

 

 

 

 

 

 

Description: Draw Arc Command: Draws an arc in PICT counterclockwise from xθ1 to xθ2, with its center at the coordinate specified in argument 1 or level 4 and its radius specified in argument 2 or level 3.

ARC always draws an arc of constant radius in pixels, even when the radius and center are specified in user-units, regardless of the relative scales in user-units of the x- and y-axes. With user-unit arguments, the arc starts at the pixel specified by (x, y) + (a, b), where (a, b) is the

rectangular conversion of the polar coordinate (xradius, xθ1). The resultant distance in pixels from the starting point to the center pixel is used as the actual radius, r'. The arc stops at the pixel

specified by (r', xθ2).

If xθ1 = xθ2, ARC plots one point. If xθ1 – xθ2 >360 degrees, 2π radians, or 400 grads, ARC draws a complete circle.

Full Command and Function Reference 3-13