flag a specified data value as NULL in one component of a field
group DVset_null {
Node_Data+IOparam &in { /* input field */
nnodes+req;
};
int+Iparam component; /* which component to set */
int+IOparam unset;
float+Iparam null_value; /* what is the NULL value */
Node_Data+Oparam &out => in; /* output field */
method+notify_val+notify_inst upd_set_null = "set_null";
} ;
DVset_null alters a field by defining a specified value as a NULL value and setting the flag that indicates the presence of NULL data to 1 ("has null data"). This is done on a per-component basis--one component may have NULL data while others do not. DVset_null can also turn off the NULL data flag.
A reference to a field with Node_Data.
An integer. Sets which component will be flagged as having NULL data. The components can be scalar or vector.
An integer. When not equal to 0, DVset_null will turn off the selected component's NULL data flag.
A float. Specifies the data value that will be treated as a NULL value. This is converted to the data type of the field before it is used.
The output is a reference to the input field. The input field has been modified so that its Node_Data Data_Array null_flag =1 and null_value is set for the component's Data_Array. DVset_null is one of the few modules that actually changes its input data field.