Small portion of simplified(!) North Atlantic food web
The last technique: Matrix Multiplication ð
In working with graphs so far we've been able to lean on our visual system to literally see if a graph is connected, or to help us spy out the minimal spanning tree or shortest route. But it's no help when graphs get moderately large or complex (see above). Which brings us to matrix multiplication. Multiplying matrices unlocks a rich set of interpretations of system graphs. This week it will enable us to tell if a graph is connected, and which nodes are reachable from which others. Next week we will use it to trace the dynamic evolution of systems using Markov models.
Matrix multiplication is a fussy procedure, but it is mechanical, and you might as well start muttering the key incantation to yourself now: "the column above times the row to the left".
And two tidbits ðŠ ð§
It's a shame that it's just as the course ends that we finally have the tools to consider some of the most interesting questions.
The Rule of 72. What do you do when there isn't an efficient, exact mathematical solution? Use a rule of thumb or heuristic.
Game trees. How do computers keep beating people at games? They build game trees to look into the future and see how it will play out.
The end is in sight! ðĪŠ (Even the emails are getting shorter)
Just two weeks of classes left and they're both short weeks, and then one day for exam prep. Count the days. Make a plan. Stick to it.
End of term awkwardness
Because of the holidays and the fact that the term ends on a Tuesday, the last two assignments are not due on Fridays. Moodle does already knows this, but I'll still point out that:
Assignment 11 is due Wednesday April 3.
Assignment 12 is due Tuesday April 9.
Always under construction â ïļ
I had to do a bunch of moving and renaming of resources on the website (because holidays). Please let me know if anything seems out of place, or you find broken links. #goodforyourkarma ð
