This function assigns a set of attribute values to an Object, over-riding any previous values. The attributes and their new values are specified via a character string, which should contain a comma-separated list of the form:

" attribute_1 = value_1, attribute_2 = value_2, ... "

where " attribute_n" specifies an attribute name, and the value to the right of each " =" sign should be a suitable textual representation of the value to be assigned. This value will be interpreted according to the attribute’ s data type.

The string supplied may also contain " printf" -style format specifiers, identified by " %" signs in the usual way. If present, these will be substituted by values supplied as additional optional arguments (using the normal " printf" rules) before the string is used.

void astSet( AstObject $\ast$this, const char $\ast$settings, ... )

this

settings

...

Object

astSet( map, " Report = 1, Zoom = 25.0" );

Sets the Report attribute for Object " map" to the value 1 and the Zoom attribute to 25.0.

astSet( frame, " Label( %d ) =Offset along axis %d" , axis, axis );

Sets the Label(axis) attribute for Object " frame" to a suitable string, where the axis number is obtained from " axis" , a variable of type int.

astSet( frame, " Title =%s" , mystring );

Sets the Title attribute for Object " frame" to the contents of the string " mystring" .

• Attribute names are not case sensitive and may be surrounded by white space.

• White space may also surround attribute values, where it will generally be ignored (except for string-valued attributes where it is significant and forms part of the value to be assigned).

• To include a literal comma in the value assigned to an attribute, the whole attribute value should be enclosed in quotation markes. Alternatively, you can use " %s" format and supply the value as a separate additional argument to astSet (or use the astSetC function instead).

• The same procedure may be adopted if " %" signs are to be included and are not to be interpreted as format specifiers (alternatively, the " printf" convention of writing " %%" may be used).

• An error will result if an attempt is made to set a value for a read-only attribute.