/**
* Returns metric tensor if specified indices have same states and
* Kronecker tensor if specified indices have different states.
*
* @param index1 first index
* @param index2 second index
* @return metric tensor if specified indices have same states and
* Kronecker tensor if specified indices have different states
* @throws IllegalArgumentException if indices have different types
* @throws IllegalArgumentException if indices have same states and non metric types
*/
public SimpleTensor CreateMetricOrKronecker(uint index1, uint index2)
{
if (IndicesUtils.getRawStateInt(index1) == IndicesUtils.getRawStateInt(index2))
{
return(createMetric(index1, index2));
}
return(createKronecker(index1, index2));
}
/**
* Returns Kronecker tensor with specified upper and lower indices.
*
* @param index1 first index
* @param index2 second index
* @return Kronecker tensor with specified upper and lower indices
* @throws IllegalArgumentException if indices have same states
* @throws IllegalArgumentException if indices have different types
*/
public SimpleTensor CreateKronecker(uint index1, uint index2)
{
byte type;
if ((type = IndicesUtils.getType(index1)) != IndicesUtils.getType(index2) || IndicesUtils.getRawStateInt((uint)index1) == IndicesUtils.getRawStateInt((uint)index2))
{
throw new ArgumentException("This is not kronecker indices!");
}
if (!isMetric(type) && IndicesUtils.getState(index2))
{
var t = index1;
index1 = index2;
index2 = t;
}
ISimpleIndices indices = IndicesFactory.createSimple(null, index1, index2);
var nd = nameManager.mapNameDescriptor(nameManager.getKroneckerName(), new StructureOfIndices(indices));
var name = nd.Id;
return(Tensor.SimpleTensor(name, indices));
}