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SyneRBI / SIRF

Main repository for the CCP SynerBI software
http://www.ccpsynerbi.ac.uk
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AcquisitionModel is missing the method norm #804

Closed paskino closed 3 years ago

paskino commented 3 years ago

Using CIL minimisation algorithms, oftentimes it is required to calculate the norm of an operator, e.g. in setting up PDHG, the 2 step sizes must be sigma * tau < (1/operator.norm())**2.

In CIL, for LinearOperator we use the PowerMethod, which is an iterative method. PowerMethod is a static method of LinearOperator and it will work with SIRF AcquisitionModels.

We cannot add a method using LinearOperator.PowerMethod from CIL as this will add a strong dependence on CIL.

We could copy the PowerMethod to SIRF at the Python level to start with.

KrisThielemans commented 3 years ago

@evgueni-ovtchinnikov can this be closed since you merged #811?

evgueni-ovtchinnikov commented 3 years ago

yes it can now, closing...