Texas Instruments TI-89 Manual Book page 306

Circular Definition
Errors
Variable-Related
Commands
Note: The Define , DelVar ,
and Local commands are
available from the Program
Editor's † Var toolbar
menu.
When evaluating a user-defined function or running a program, you
can specify an argument that includes the same variable that was
used to define the function or create the program. However, to avoid
errors, you must assign a value for
Circular definition
that are used in evaluating the function or running the program.
For example:
x+1!x
– or –
For i,i,10,1
Disp i
EndFor
Command Description
§ key
Stores a value to a variable. As on the Home screen,
pressing § enters a ! symbol.
Archive Moves specified variables from RAM to user data
archive memory.
Lets you create a data variable based on the graph
BldData
information entered in the Y=Editor, Window
Editor, etc.
Copies the contents of a variable.
CopyVar
Defines a program (subroutine) or function variable
Define
within a program.
DelFold Deletes a folder. All variables in that folder must be
deleted first.
Deletes a variable.
DelVar
Returns the name of the current folder.
getFold
Returns a string that indicates the data type (
getType
, etc.) of a variable.
LIST
Declares one or more variables as local variables.
Local
Locks a variable so that it cannot be accidentally
Lock
changed or deleted without first being unlocked.
Moves a variable from one folder to another.
MoveVar
NewData Creates a data variable whose columns consist of a
series of specified lists.
Creates a new folder.
NewFold
Creates a picture variable based on a matrix.
NewPic
Renames a variable.
Rename
Moves specified variables from user data archive
Unarchiv
memory to RAM.
Unlocks a locked variable.
Unlock
Causes a Circular definition error message if x
or i does not have a value. The error does not
occur if x or i has already been assigned a value.
Chapter 17: Programming
or variables
x i
,
EXPR
289