Hp 49g+ User Manual download pdf (Page 264)

Defining functions that use lists

In Chapter 3 we introduced the use of the DEFINE function ( „à) to

create functions of real numbers with one or more arguments. A function

defined with DEF can also be used with list arguments, except that, any

function incorporating an addition must use the ADD operator rather than the

plus sign (+). For example, if we define the function F(X,Y) = (X-5)*(Y-2),

shown here in ALG mode:

we can use lists (e.g., variables L1 and L2, defined earlier in this Chapter) to

evaluate the function, resulting in:

Since the function statement includes no additions, the application of the

function to list arguments is straightforward. However, if we define the

function G(X,Y) = (X+3)*Y, an attempt to evaluate this function with list

arguments (L1, L2) will fail:

To fix this problem we can edit the contents of variable @@@G@@@ , which we can

list in the stack by using …@@@G@@@,

to replace the plus sign (+) with ADD:

Hp 49g+ User Manual Page 264