mrphy.__init__
A MRI excitation physics module.
About MRphy.py:
MRphy.py
provides the following constant and submodules:
Constant:
γH
: water proton gyro frequency, “4257.6 Hz/Gauss”.
Submodules:
General Comments:
Variable naming convention:
A trailing _
in a variable/attribute name indicates compactness, i.e.
instead of size (N, *Nd, ...)
, the variable/attributes size
(N, nM, ...)
.
For instance:
A field map variable Δf
may be of size (N, nx, ny, nz)
, while its
compact countarpart Δf_
has a size of (N, nM)
.
Special keywords used in documentations:
N
: batch sizenM
: the number of spinsNd
: A int-tuple for array size, e.g.:Nd = (nx, (ny, (nz)))
. In python convention,*
unpacks a tuple. Therefore,(N, *Nd) === (N, nx, ny, nz)
.nT
: the number of time pointsxy
: the dimension has length of2
xyz
: the dimension has length of3
⊻
: Either or. When used in enumerating function keywords arguments, it means the function accepts at most one of the keywords in a set as an input, e.g.,Δf ⊻ Δf_
means accepting eitherΔf
orΔf_
. When used in specifying variable dimensions, it means the dimension tuple can be one of the size tuple set, e.g.(N, nM ⊻ *Nd, xyz)
means accepting dimension either(N, nM, xyz)
or(N, *Nd, xyz)
.