On Sat, 13 Oct 2012, Logan Kelly wrote: > I am using GRETL 1.9.9 on a Win 7 64bit machine. I found a quirk that may > be a bug. I found that > > bundle BundleOfMatrixs > matrix BundleOfMatrixs["test"] = {} > matrix test = {1,2,3,4} > BundleOfMatrixs["test"] |= test > > yields the following error message > > '|=' : only defined for matrices > > Error executing script: halting >> BundleOfMatrixs["test"] |= test > > but that > > bundle BundleOfMatrixs > matrix BundleOfMatrixs["test"] = {} > matrix test = {1,2,3,4} > BundleOfMatrixs["test"] = BundleOfMatrixs["test"]|test > > works just fine. Hmm, not sure this is a bug. This basic idea with bundles is that if you want to do anything with a matrix (or any other sort of object) from inside the bundle you have to extract it first (which makes a copy of the object). At first I was a little surprised that even your second formulation worked, but on reflection it's OK: on the right hand side, BundleOfMatrixs["test"] produces an anonymous matrix which is a copy of the one in the bundle, to which you concatenate another matrix; then the "=" operation replaces the bundle content under the key "test" with the new right-hand side matrix. That is, your second version is an acceptable variant of the canonical form matrix m = BundleOfMatrixs["test"] # extract m |= {1,2,3,4} # modify BundleOfMatrixs["test"] = m # re-assign I guess one could argue that your first formulation should be taken as shorthand for your second, but I have to say it doesn't "look right" to me; I would not have expected it to work -- though I admit I'd have had difficulty predicting the error message.