Handling errors related to attached formulas – Texas Instruments TI-86 User Manual

Page 177

Chapter 11: Lists

165

11LISTS.DOC TI-86, Chap 11, US English Bob Fedorisko Revised: 02/13/01 2:30 PM Printed: 02/13/01 3:03 PM Page 165 of 16

You can successfully attach to a list a formula that does not yet resolve to a list. For
example, you can attach

xStat"

to the list name

BY5

with no elements stored to

xStat

However, if you attempt to display

BY5

when

xStat

has no elements, an error occurs.

When you attach such a formula to a list name in the list editor, the formula is successfully
attached, but an error occurs. This is because the list editor attempts to execute the
formula immediately after attaching it to the list name.

To view the list editor again, you must return to the home screen and either enter
something to cause the formula to resolve to a list or remove the attached-formula list from
the list editor using the

LIST

OPS

menu item

SetLE

(page 161).

Handling Errors Related to Attached Formulas

On the home screen, you can attach to a list a formula that references another list that has
no elements (dimension is

; page 161). However, you cannot display the attached-formula

list in the list editor or on the home screen until you enter at least one element to the list
that the formula references.

Tip:

If an error menu is returned when you attempt to display an attached-formula list in

the list editor, you can select

GOTO

, write down the formula that is attached to the list

name, and then press : b to detach (clear) the formula. Then you can use the list
editor to find the source of the error. After making the appropriate changes, you can re-
attach the formula to the list name.

If you do not want to clear the formula, you can select

QUIT

, display the referenced list on

the home screen, and find and edit the source of the error. To edit an element of a list on
the home screen, store the new value to listName

(

element#

)

(page 155).

All elements of a list
referenced by an attached
formula must be valid for the
attached formula.