A note on scalable frames

Understand

We study the problem of determining whether a given frame is scalable, and when it is, understanding the set of all possible scalings.

• We show that for most frames this is a relatively simple task in that the frame is either not scalable or is scalable in a unique way, and to find this scaling we just have to solve a linear system.
• We also provide some insight into the set of all scalings when there is not a unique scaling.
• In particular, we show that this set is a convex polytope whose vertices correspond to minimal scalings.