From time-to-time we stumble across funny quirks while using MATLAB®. The latest came as one of our developers accidentally mis-keyed a few characters. With 5 characters on the command line, you too can get a message about tree cats seeing your bad code (followed by a nasty seg fault, so beware). Try this: >> a()@a tree_cat sees bad code * Subsref [4] * M_ID 0(5) which * M_LRB 5(1) * ExprList [1] * M_ID 6(1) e * M_RRB 7(1) tree_cat sees bad code * Subsref [4] * M_ID 0(5) which * M_LRB 5(1) * ExprList [1] * M_ID 6(1) e * M_RRB 7(1) Top Secret: Part of Jacket’s GPU runtime involves monkeys obtaining bananas for optimal performance. While we can’t …
Accelerate Computer Vision Data Access Patterns with Jacket & GPUs
For computer vision, we’ve found that efficient implementations require a new data access pattern that MATLAB does not currently support. MATLAB and the M language is great for linear algebra where blocks of matrices are the typical access pattern, but not for Computer Vision where algorithms typically operate on patches of imagery. For instance, to pull out patches of imagery in M, one must do a double nested for loop, A = rand(100,100) for xs = -W:W for ys = -W:W patch(xs+W+1, ys+W+1) = A(xs+1+x, ys+1+y); end end …with guards for boundary conditions, etc. It gets even more complicated with non-square patches. On top of that, these implementations don’t translate to the GPUs memory hierarchy at all and are thus …