On Sat, 30 Jul 2011 10:41:52 -0500 Jonathan Wright <j...@jondw.com> wrote:
> On Sat, 30 Jul 2011 09:34:02 -0500 > Jonathan Wright <j...@jondw.com> wrote: > > > On Sat, 30 Jul 2011 08:52:53 -0500 > > Jonathan Wright <j...@jondw.com> wrote: > > > > > > > > Hello, > > > > > > I'm trying to extend the Matrix class by making it able to add and > > > subtract matrices. So far I've implemented the following code to > > > add: > > > > > > + aMatrix > > > | newMatrix rowCount columnCount sum | > > > rowCount := self rowCount. > > > columnCount := self columnCount. > > > newMatrix := Matrix rows: rowCount columns: columnCount. > > > > > > 1 to: rowCount do: [ :selectRow | > > > 1 to: columnCount do: [ :selectColumn | > > > sum := (self at: selectRow at: selectColumn) + > > > (aMatrix at: selectRow at: > > > selectColumn). newMatrix at: selectRow at: selectColumn put: > > > sum.]]. ^newMatrix. > > > > > > Now I want to implement a method for subtracting matrices. > > > However, I'd like to use the same code. I tried to implement an > > > operand selector, however, it errors out. > > > > > > Something like this: > > > > > > operand: operand matrix: aMatrix > > > | newMatrix rowCount columnCount sum | > > > rowCount := self rowCount. > > > columnCount := self columnCount. > > > newMatrix := Matrix rows: rowCount columns: columnCount. > > > > > > 1 to: rowCount do: [ :selectRow | > > > 1 to: columnCount do: [ :selectColumn | > > > sum := (self at: selectRow at: selectColumn) > > > operand (aMatrix at: selectRow at: > > > selectColumn). newMatrix at: selectRow at: selectColumn put: > > > sum.]]. ^newMatrix. > > > > > > I know this is not SmallTalk convention, but how should I pursue > > > something like this? > > > > > > Thank You, > > > Jonathan > > > _______________________________________________ > > > Beginners mailing list > > > Beginners@lists.squeakfoundation.org > > > http://lists.squeakfoundation.org/mailman/listinfo/beginners > > > > > > > I answered my own question. How I love being able to look at all > > the source code in this handy Browser in Squeak! > > > > I implemented the following: > > > > perform: anOpperator with: aMatrix > > | newMatrix rowCount columnCount result | > > rowCount := self rowCount. > > columnCount := self columnCount. > > newMatrix := Matrix rows: rowCount columns: columnCount. > > > > 1 to: rowCount do: [ :selectRow | > > 1 to: columnCount do: [ :selectColumn | > > result := (self at: selectRow at: selectColumn) > > perform: anOpperator with: (aMatrix at: selectRow at: selectColumn). > > newMatrix at: selectRow at: selectColumn put: > > result.]]. ^newMatrix. > > > > > > where the subtraction/addition looks like this: > > subtractMatrix := matrixOne perform: #- with: matrixTwo. > > _______________________________________________ > > Beginners mailing list > > Beginners@lists.squeakfoundation.org > > http://lists.squeakfoundation.org/mailman/listinfo/beginners > > > > Something I don't understand about this however. Why does the > "result := (self at: selectRow at: selectColumn) perform: anOpperator > with: (aMatrix at: selectRow at: selectColumn)" > statement use the Object class and not the Matrix class I extended? > Oh because "(self at: selectRow at: selectColumn)" returns an Integer not a Matrix, duh. Sorry for so many comments. _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
