MHB Solving 2x2 Matrix Projection Problem: Strang's Approach

arrow27
Messages
7
Reaction score
0
Many important techniques in fields such as CT and MR imaging in medicine,
nondestructive testing and scientific visualization are based on trying
to recover a matrix from its projections. A small version of the problem
is given the sums of the rows and columns of a 2 x 2 matrix, determine the
elements of the matrix. Solve this problem or show why it cannot be solved(Strang)
 
Physics news on Phys.org
arrow27 said:
Many important techniques in fields such as CT and MR imaging in medicine,
nondestructive testing and scientific visualization are based on trying
to recover a matrix from its projections. A small version of the problem
is given the sums of the rows and columns of a 2 x 2 matrix, determine the
elements of the matrix. Solve this problem or show why it cannot be solved(Strang)
What have you tried so far? Have you looked at both possible outcomes? In other words, have you tried (a) to prove the result, and (b) to find a counterexample? A possible counterexample might consist of two different matrices with the same row sums and column sums.
 
Thread 'Derivation of equations of stress tensor transformation'
Hello ! I derived equations of stress tensor 2D transformation. Some details: I have plane ABCD in two cases (see top on the pic) and I know tensor components for case 1 only. Only plane ABCD rotate in two cases (top of the picture) but not coordinate system. Coordinate system rotates only on the bottom of picture. I want to obtain expression that connects tensor for case 1 and tensor for case 2. My attempt: Are these equations correct? Is there more easier expression for stress tensor...
Back
Top