释义 |
Direction CosineLet be the Angle between and , the Angle between and , and the Angle between and . Then the direction cosines are equivalent to the coordinatesof a Unit Vector ,
| (1) |
| (2) |
| (3) |
From these definitions, it follows that
| (4) |
To find the Jacobian when performing integrals over direction cosines, use
The Jacobian is
| (8) |
Using
so
Direction cosines can also be defined between two sets of Cartesian Coordinates,
| (13) |
| (14) |
| (15) |
| (16) |
| (17) |
| (18) |
| (19) |
| (20) |
| (21) |
Projections of the unprimed coordinates onto the primed coordinates yield
and
Projections of the primed coordinates onto the unprimed coordinates yield
and
| (31) |
| (32) |
| (33) |
Using the orthogonality of the coordinate system, it must be true that
| (34) |
| (35) |
giving the identities
| (36) |
for and , and
| (37) |
for . These two identities may be combined into the single identity
| (38) |
where is the Kronecker Delta.
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