classUnderlying

A quaternion is a four-part hyper-complex number used in three-dimensional representations. The four parts of the quaternion are of data type single or double.

Create two quaternions, one with an underlying data type of single, and one with an underlying data type of double. Verify the underlying data types by calling classUnderlying on the quaternions.

qSingle = quaternion(single([1,2,3,4]))

qSingle = quaternion
     1 + 2i + 3j + 4k

classUnderlying(qSingle)

ans = 
'single'

qDouble = quaternion([1,2,3,4])

qDouble = quaternion
     1 + 2i + 3j + 4k

classUnderlying(qDouble)

ans = 
'double'

You can separate quaternions into their parts using the parts function. Verify the parts of each quaternion are the correct data type. Recall that double is the default MATLAB® type.

[aS,bS,cS,dS] = parts(qSingle)

aS = single

1

bS = single

2

cS = single

3

dS = single

4

[aD,bD,cD,dD] = parts(qDouble)

aD = 
1

bD = 
2

cD = 
3

dD = 
4

Quaternions follow the same implicit casting rules as other data types in MATLAB. That is, a quaternion with underlying data type single that is combined with a quaternion with underlying data type double results in a quaternion with underlying data type single. Multiply qDouble and qSingle and verify the resulting underlying data type is single.

q = qDouble*qSingle;
classUnderlying(q)

ans = 
'single'