/**
* Returns metric tensor with specified indices.
*
* @param index1 first index
* @param index2 second index
* @return metric tensor with specified indices
* @throws IllegalArgumentException if indices have different states
* @throws IllegalArgumentException if indices have different types
* @throws IllegalArgumentException if indices have non metric types
*/
public SimpleTensor CreateMetric(uint index1, uint index2)
{
byte type;
if ((type = IndicesUtils.getType(index1)) != IndicesUtils.getType(index2) ||
!IndicesUtils.haveEqualStates(index1, index2) ||
!metricTypes.Get(type))
{
throw new ArgumentException("Not metric indices.");
}
var indices = IndicesFactory.createSimple(null, index1, index2);
var nd = nameManager.mapNameDescriptor(nameManager.GetMetricName(), new StructureOfIndices(indices));
var name = nd.Id;
return(Tensor.SimpleTensor(name, indices));
}
public bool isMetric(SimpleTensor t)
{
return(nameManager.isKroneckerOrMetric(t.GetName()) &&
IndicesUtils.haveEqualStates(t.GetIndices()[0], t.GetIndices()[1]));
}
/**
* Returns {@code true} if specified tensor is a metric tensor
*
* @param t tensor
* @return {@code true} if specified tensor is a metric tensor
*/
public bool IsMetric(SimpleTensor t)
{
return(nameManager.IsKroneckerOrMetric(t.Name) &&
IndicesUtils.haveEqualStates(t.Indices[0], t.Indices[1]));
}