Alan Dougherty has joined the conference. Kyla Johnson has joined the conference. Betty Strong has joined the conference. Celia Einhorn has joined the conference. Irene Lee has joined the conference. Dianne Kemp has joined the conference. Netta Noble has joined the conference. challengebetsy: Irene do you want to suggest a solution? challengebetsy: Or an alternative? challengebetsy: Web CT is choking for some reason or other chidhkratzer: I am talking with NMSU webct support right now. chtkjohn: my whole computer is locking up not just my connection. celiaeinhorn: Just written irene_anne_lee: written only please celiaeinhorn: Great that you have called, David! challengedianne: Yesterday, my computer locked up too. irene_anne_lee: Let's turn our voice off irene_anne_lee: so as not to get background noise betty_strong2004: Betty and mavis are both here irene_anne_lee: So here we are! Happy Thursday Dale Henderson has joined the conference. irene_anne_lee: I was thinking that we should do the Starlogo Q&A right here challengebetsy: Good idea! betty_strong2004: invite pam irene_anne_lee: does anyone have a question about what we did yesterday irene_anne_lee: Betsy, did you invite everyone to join? chidhkratzer: NMSU is having hardware problems with cabasa and have been working on it all week. challengedianne: How do I begin a program? Can I use an existing program and fine tune it to our group's goals? challengebetsy: Yes - but missed Pam ,i guess though she is on my list of people invited - just invited again irene_anne_lee: yes, you may do that. But with care! irene_anne_lee: could you tell me more about what you are proposing? irene_anne_lee: If you would rather not, that's okay too challengedianne: Irene will you be available to assist me in getting started? I have some ideas I'd like to bounce back in forth with you. My team desires to build a population model adding economic factors to the program. irene_anne_lee: yes most certainly challengedianne: Is email good or can we set up a time on yahoo messenger? irene_anne_lee: your preference. I could do either. Let's start with an online YIM meeting.... chtkjohn: i am on Dianne's team. We may use one part with Starlogo and the other with a more 'traditional' model. irene_anne_lee: Sounds great! It is always useful to look at a problem from an agent based perspective as well as from another... One helps validate the other, or not challengedianne: Alan, traditional model? Do you mean with another type of programming? challengedianne: When building a program, how many turtles should I begin with? irene_anne_lee: Could be a math model in excel, could be a different program alanrayaisc: Well, I think that the math on Excell would be a 'traditional model' with graphs etc. irene_anne_lee: You can start with many many turtles though Starlogo will seem to be very slow, I've seeen 10,000 challengedianne: gotcha Alan. I understand. Thank you. celiaeinhorn: Dick could also help out your team, Dianne and Alan and Kyla! irene_anne_lee: Kids will try 100,000 and bring the program to its knees challengedianne: What does wiggle represent? irene_anne_lee: wiggle represents a random walk betty_strong2004: the invitation to pam did not reach her, she needs on, could you invite her again? challengebetsy: i just did about 15 seconds ago! thanks! irene_anne_lee: usually it is implemented using a rt random some number followed by a lt random some number challengedianne: Does wiggle make the turtle go in random directions? Kyla Johnson has left the conference. Kyla Johnson has joined the conference. challengedianne: Is there directions on how I can approach building my model at the StarLogo site? chtkjohn: i thought i was already on, who knows. irene_anne_lee: Well, it makes the turtle go in a direction that is probablistic. Meaning that if I said "rt random 90 lt random 90" what really happens iss... maybe you should try it... irene_anne_lee: It took me a while to figure what was reeally going on with a wiggle..... irene_anne_lee: Directions on how to approach building a model are available on WebCT under courses->Starlogo challengedianne: How do we control what occurs on the canvas? Underneath the turtles irene_anne_lee: I think thte section is called IAL - model design form or something like that. It is a word doc thtat walks you through designing a model irene_anne_lee: Hi Dianne, the patches that make up the canvas can be changed in various ways irene_anne_lee: one way is to actually draw on the canvas, another is to ask a turtle to draw on the canvas using the stamp command irene_anne_lee: another way is to import an image to be used as the canvas challengedianne: When building my model should I consider the canvas, or just focus on what I can see-the turtles? So I can take another picture on a website to be my canvas? irene_anne_lee: There are a set of commands that operate on the patches such as diffuse which "waters down" the image on the canvas, think of it as diffusing the color. You can find a list of these in the Sttarlogo online docs challengedianne: Thank you Irene. I'll let someone else ask questions now. Thank you. I'll be in touch. irene_anne_lee: Depends on the problem. For instance, there is a model of "hill climbing" where agents wander around until they find the peaks.... in this case the canvas represents the terrain and is very important irene_anne_lee: You can import other pictures to be the canvas. I once used a picture of a friend as the terrain for the turtles to wander around. irene_anne_lee: strange but true Levi Valdez has joined the conference. irene_anne_lee: Back to the wiggle problem. Let's simplify it to rt random 10 lt random 10. irene_anne_lee: So the first thing that happens is that the turtle makes a right turn at some angle between 0 and 9. irene_anne_lee: this should be equally distributed as random really returns a random value Pam Arzu has joined the conference. pamrdoodle2002: okay i'm here...wow.. irene_anne_lee: then thte turtle makes a left turn of some angle between 0 and 9 irene_anne_lee: but what are all the possibilities of the composite of the two turns? irene_anne_lee: Think of a two-dimensional matrix with right turn amount as the columns and left turn amounts as the rows.... so 0 - 9 along the horizontal axis and 0 - 9 along the vertical axis... How many ways are there to get a net effect of 0 (for the rt followed by the lt) irene_anne_lee: anyone??? alanrayaisc: 9? irene_anne_lee: close Alan1 irene_anne_lee: actually I think it is 10, can you explain how you figured it out alanrayaisc: Well, okay, 10. since there are 10 values. irene_anne_lee: yes irene_anne_lee: right, these 10 values run along the diagonal of the matrix from top left to bottom right betty_strong2004: pam, we are only typing. No headphones alanrayaisc: In a 10 by 10 matrix there would be 10 'places' where the numbers would cancel each other out. pamrdoodle2002: no problem...I am reading along irene_anne_lee: they represent "rt 0 lt 0", "rt 1 lt 1", "rt 2 lt 2", "rt 3 lt 3" ..... and so on up to "rt 9 lt 9" . All these combinations have a net effect of no turn irene_anne_lee: Okay, did I lose anyone? irene_anne_lee: So now find all the ways to make 1 degree turn to the right.... how many ways exist? alanrayaisc: Again, there would be 10... irene_anne_lee: "rt 1 lt 0", "rt 2 lt 1", "rt 3 lt 2" ..... irene_anne_lee: nope not 10, but close pamrdoodle2002: hummm irene_anne_lee: think back to the matrix.... this set would be the diagonal line just above the diagonal where a net effect of zero was. alanrayaisc: so 9. irene_anne_lee: YES!!!!! irene_anne_lee: so what about thte ways to make a net effect of 2 degrees turn to the right??? alanrayaisc: 8 irene_anne_lee: Okay, now you are cooking!!! What is the pattern irene_anne_lee: Does the same apply for the net effect of a one degree left hand turn? alanrayaisc: Each diagonal line has one less 'amount' but one more value of the angle. irene_anne_lee: Cool, so back to wiggling, what does this mean in the context of wiggling? Jeff Raloff has joined the conference. irene_anne_lee: any guesses? irene_anne_lee: help.... is anyone out there? alanrayaisc: I'm awaiting your explanation... : ) irene_anne_lee: oh okay.... so what it means in terms of wiggling is that there is a higher probability of the turtle moving straight ahead than of the turtle turning to either side. irene_anne_lee: And the probability drops as the angle gets larger!!!! irene_anne_lee: Smart turtles.. irene_anne_lee: Does that make sense? alanrayaisc: Got it. challengedianne: I think so! Pam Arzu has joined the conference. irene_anne_lee: if you really wanted a turtle to turn a random amount before each step, how could you do thiss? alanrayaisc: Pick a random amount between 0 and 360 irene_anne_lee: yup, "rt random 360" would do it ... Great! betty_strong2004: Would we pick a number between 1 and 359? betty_strong2004: never mind irene_anne_lee: yes Betty alanrayaisc: That would prevent an angle of zero... pamrdoodle2002: but wouldn't an angle of 0 send them forward? irene_anne_lee: random 360 returns a value between 0 and 359 pamrdoodle2002: okay alanrayaisc: That would make it truly random if they could still go forward. irene_anne_lee: turning an angle of 0 is the same as not turning, correct irene_anne_lee: So think about the difference between the path a wiggling turtle would make versus a truly random turtle irene_anne_lee: how about trying to implement this in starlogo? irene_anne_lee: you can use the pd command (stands for pendown) so a turtle could leave a trail behind itt irene_anne_lee: the trail will be the same color as the turtle irene_anne_lee: Well I think it is time to wrap up. Try this if you would like to. you could have one buttton call a turtle procedure that does the wiggle and another button that calls a turtle procedure to do the truly random walk challengedianne: wiggling turtle-you've commanded-given directions-you know its direction-predictable. a random turtle is erratic and unpredictable challengedianne: Thank you Irene. I will try you suggestions. irene_anne_lee: I think of a wiggling turtle as kind of a some what drunk turtle, it staggers around but mostly goes straight ahead irene_anne_lee: you are welcome Dianne Kemp has left the conference. irene_anne_lee: well maybe that is not a good way of looking at it!!! irene_anne_lee: Thanks for tuning in! challengebetsy: A little interruption - cabasa is still down irene_anne_lee: oh dear alanrayaisc: How about this Irene. Wiggling is like putting on a rough surface... No sure control but at least you have an IDEA of where you go... Random is hitting the ball blindfolded after twirling around. irene_anne_lee: But unlike putting where the golf ball is directed to the hole, in the wiggle once the turtle turns, it is facing a different direction (straight ahead now means something new0