Routines (alphabetical) > Object Classes > Graphics Object Classes > IDLgrROI::Init

# IDLgrROI::Init

Syntax | Return Value | Arguments | Keywords | Version History

The IDLgrROI::Init function method initializes an Object Graphics region of interest.

Note: Init methods are special life cycle methods, and as such cannot be called outside the context of object creation. This means that in most cases, you cannot call the Init method directly. There is one exception to this rule: if you write your own subclass of this class, you can call the Init method from within the Init method of the subclass.

## Syntax

Obj = OBJ_NEW( 'IDLgrROI' [, X[, Y[, Z]]] [, PROPERTY=value])

or

Result = Obj->[IDLgrROI::]Init([X[, Y[, Z]]] [, PROPERTY=value]) (In a lifecycle method only.)

## Return Value

When this method is called indirectly, as part of the call to the OBJ_NEW function, the return value is an object reference to the newly-created object.

When called directly within a subclass Init method, the return value is 1 if initialization was successful, or zero otherwise.

## Arguments

### X

A vector providing the X components of the vertices for the region. If the Y and Z arguments are not specified, X must be a two-dimensional array with the leading dimension either 2 or 3 ([2, *] or [3, *]), in which case, X[0, *] represents the X values, X[1, *] represents the Y values, and X[2, *] represents the Z values. This argument is stored as double precision floating point values if the argument variable is of type DOUBLE or if the DOUBLE property is non-zero. Otherwise it is converted and stored as single precision floating point.

### Y

A vector providing the Y components of the vertices. This argument is stored as double precision floating point values if the argument variable is of type DOUBLE or if the DOUBLE property is non-zero. Otherwise it is converted and stored as single precision floating point.

### Z

A scalar or vector providing the Z components of the vertices. If not provided, Z values default to 0.0. This argument is stored as double precision floating point values if the argument variable is of type DOUBLE or if the DOUBLE property is non-zero. Otherwise it is converted and stored as single precision floating point.

## Keywords

Any property listed under IDLgrROI Properties that contains the word “Yes” in the “Init” column of the properties table can be initialized during object creation using this method. To initialize the value of a property, specify the property name as a keyword set equal to the appropriate property value.

All other keywords are passed to the superclass of this object.

## Version History

5.3 | Introduced