Adams Basic Package > Adams View > View Command Language > function > function modify

function modify

A function allows you to define a new function in terms of an Adams View expression. The function modify command allows you to modify an existing user written function.

You may reverse this modification at a later time with an UNDO command.

Format:

function modify
function_name =	existing expr_function
new_function_name =	new expr_function
text_of_expression =	string
argument_names =	string
type =	result_type
comments =	string
category =	func_category

Example:

! Already have a function named "This"

VARIABLE CREATE VARIABLE_NAME=Example REAL_VALUE=(This(1))

FUNCTION MODIFY FUNCTION_NAME=This NEW_FUNCTION_NAME=That

LIST_INFO VARIABLE VARIABLE_NAME=Example

! You will see that the real value is (That(1))

Description:

Parameter	Value Type	Description
function_name,	Existing Expr_function	Specifies the name of the user-written function you are modifying. You should choose a name which is meaningfully related to the operation that the function is performing.
New_function_name	New Expr_function	Allows you to change the name of an already existing function. When you change the function's name, all references to it also change.
text_of_expression,	String	The TEXT_OF_EXPRESSION parameter defines the computation to be performed by the function.
argument_names	String	The ARGUMENT_NAMES parameter allows you to specify the names of the formal arguments in your function.
type	Array, Integer, Location_orientation, Object, Real, String	The TYPE parameter of a function indicates the type of the returned value.
omments	String	The COMMENTS parameter allows you to add comments to the function for documentation purposes. The strings are stored in the database and written to command files.
category	User, String, Math, Modelling, Loc_ori, Matrix_array, Database_object, Misc	Specifies which category this function should be classified under.

Extended Definition:

1. Remember that the value of the argument “text_of_expression” should be a character string, NOT an expression.

FUNCTION CREATE FUNCTION_NAME=SSQDIF &

ARGUMENT_NAMES=Array1, Array2 &

TEXT_OF_EXPRESSION="SSQ(Array1-Array2)" &

COMMENT_STRING="Compute sum of squares of differences between arguments" &

TYPE=real

2. The argument_names you specify are associated by position with the actual arguments when you invoke the function.

Using the following as an example:

FUNCTION CREATE FUNCTION_NAME=MyFunc ARGUMENT_NAMES=Arg1, Fred &

TEXT_OF_EXPRESSION="sqrt(Fred) * Arg1"

VARIABLE CREATE VARIABLE_NAME=TestVariable &

REAL_VALUE=(MyFunc(1+1, 9) + 4)

The first formal argument "Arg1" is associated with the value 2 (computed from 1+1); the second argument "Fred" is associated with the value 9. The resulting value for "TestVariable" is sqrt(9) * 2 + 4 = 10.