modelType

<xs:attribute name="modelType" use="required">
  <xs:simpleType>
    <xs:restriction base="xs:string">
      <xs:enumeration value="regression"/>
      <xs:enumeration value="generalLinear"/>
      <xs:enumeration value="multinomialLogistic"/>
      <xs:enumeration value="ordinalMultinomial"/>
      <xs:enumeration value="generalizedLinear"/>
      <xs:enumeration value="CoxRegression"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>