Integrate a new Linear Operator

This examples is for a SLIMpy user who is familiar with the SLIMpy vector and linear operator API. In this example I will go through the steps to create a new linear operator in SLIMpy.

Learing objectives:

• Add a new Linear Operator to SLIMpy
• Gain more understanding about SLIMpy's AST

Inputs:

• None so far

Python Modules:

• new_fft_slimpy.py contains a slimpy fft linear operator
• new_fft_rsf_integration.py contains the rsf definition of the fft operator

Outputs:

• None so far

Prerequisite:

• SLIMpy and ContribSLIMpy
• Madagascar
• SCons

Walkthrough

There are two parts to createing a linear operator in SLIMpy:

• A Python class that represents the operator in SLIMpy, found in new_fft_slimpy.py
• A Python class that defines how a plugin may use the operator, found in new_fft_rsf_integration.py

In this example the operator class will be an fft transfrom and the plugin definition will be RSF. We need to import both of those python modules to get a working linear operator in RSF. if we neglected to import new_fft_rsf_integration.py the code would give us an error when it tries to execute the fft1X executable which does not exist. Since fft1X is not defined in SLIMpy's RSF plugin, SLIMpy uses its best guess on how to use fft1X with RSF.

Try it yourself in interactive python mode with the fft1X do not import new_fft_rsf_integration. You will see that fft1X is a fully formed linear operotor. Without the rsf information SLIMpy will not give you error checking when the operator is created or applied, and the domain is known but the range is not. the range of the operator will become an instance of the voidSpace class.