I am trying to calculate the length, or radial distance, of dyads1 and dyads2 (comparable to L1 from dtifit). Bedpostx outputs a mean theta and phi value, but not the r value. Is it possible to calculate this length index? When I initially tried using the Pythagorean theorem to calculate the vector length using the X, Y, and Z of each dyad it yielded a value of 1, presumably because these values range from -1 to 1 rather than being cartesian coordinates? Thus, is it possible to convert these values to calculate the length?
Many thanks in advance,
Ilana
|