System Matrices
For loading the system matrix, one could in principle again call measData
but there is again a high level function for this job. Since system functions can be very large it is crucial to load only the subset of frequencies that are used during reconstruction The high level system matrix loading function is called getSystemMatrix
and has the following interface:
function getSystemMatrix(f::MPIFile,
frequencies=1:rxNumFrequencies(f)*rxNumChannels(f);
bgCorrection=false,
loadasreal=false,
kargs...)
loadasreal
can again be used when using a solver requiring real numbers. The most important parameter is frequencies
, which defaults to all possible frequencies over all receive channels. In practice, one will determine the frequencies using the the Frequency Filter functionality. The parameter bgCorrection
controls if a background correction is applied while loading the system matrix. The return value of getSystemMatrix
is a matrix of type ComplexF32
or Float32
with the rows encoding the spatial dimension and the columns encoding the dimensions frequency, receive channels, and patches.