Plasma profile data¶
profiletools
is primarily designed for working with profile data from
magnetic confinement fusion devices, namely the Alcator C-Mod tokamak at MIT.
The BivariatePlasmaProfile
class is an extension
of Profile
designed for this particular use case.
Data model¶
Plasma profile data are functions of space (1, 2 or 3 coordinates) and time (hence the term “bivariate” even when X_dim is greater than 2). Time is always the first column in X, with the remaining spatial coordinates forming the other columns.
Tokamak coordinate systems¶
BivariatePlasmaProfile
uses eqtools
(https://github.com/PSFCPlasmaTools/eqtools/, http://eqtools.readthedocs.org/)
to support the myriad coordinate systems used in tokamak research. Coordinate
transforms are handled using the
convert_abscissa()
method.
Constraints for Gaussian process regression¶
BivariatePlasmaProfile
provides two methods for
adding constraints to the Gaussian process created with
create_gp()
:
constrain_slope_on_axis()
applies a zero slope constraint at the magnetic axis and
constrain_at_limiter()
applies approximate zero slope and value constraints at the location of the
limiter. Note, however, that both of these constraints are applied automatically
when calling create_gp()
. You
can disable them using the constrain_slope_one_axis and constrain_at_limiter
keywords to create_gp()
, and
you can influence their behavior with the axis_constraint_kwargs and
limiter_constraint_kwargs keywords.