Graphing Stories I Want You To Make For Me

Y’all have five days left to film fifteen seconds of video, make a graph, and upload them to Graphing Stories. Here’s my wish list:

  1. Someone climbing up a ladder and jumping off a diving board (height above water).
  2. Someone riding a merry-go-round or carousel (distance from center, distance traveled, height off ground).
  3. Someone riding an elevator, watching the lights change as the floors pass by (height above ground floor).
  4. An airplane taking off (elevation).
  5. Someone driving up to a stoplight and then a stop sign (speed, distance from camera).
  6. A step function. Any step function.
  7. Someone throwing a boomerang (distance of boomerang from thrower).
  8. Someone running the bases at a baseball diamond (distance from home plate, distance from the pitcher’s mound).
  9. Someone riding a ferris wheel (height above ground, distance from center, linear velocity, angular velocity).

Add yours to the comments. Better yet, make it and submit it!

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.


  1. I can probably get some video up a ladder and off a diving platform in a month or so. Heading to my summer job next week at a camp in northern Wisconsin. It might be a bit to cold to do it when I first get there though.

  2. Monty Zukowski

    May 22, 2011 - 7:42 pm -

    I thought of a step function though unfortunately I don’t have a tachometer so I can’t video it. Gear number, engine speed, speedometer speed.

  3. Joshua Schmidt

    May 22, 2011 - 8:15 pm -

    I just finished recording my graphing story today, and I don’t want to part with it. The baseball one would be really easy too! I could easily get some kids to help me out with that one.

  4. For a step function, maybe the activity is a gambling activity, and the function is how much money you have as a function of time?

  5. I’ve got the step function covered!

    Monty, is your function really a step function? The engine won’t instantly change speeds when I shift gears; it’s a differentiable and continuous change, no?

  6. Andrew Shauver

    May 23, 2011 - 4:27 am -

    I recorded a very simple step function: Drinking water through a straw. Because of the need to exhale and swallow the water, you pull in some water and stop and pull some more water in and then stop and then pull, and then stop.

    I should have it uploaded by tomorrow afternoon.

  7. Step function: the score reels on an old pinball machine… (sorry, no access to a game with score reels). Or the score on anything, really — heh, I should film my kid playing this Little Tikes basketball game. It shows the score… :)

    Gear number is a step function, I think, although it’s an example a lot of students won’t understand because they’ve never driven a car — and some others would never have seen a stick shift!

    Drinking water through a straw is not a step function, there is a continuous change, just a very quick one. A step function goes directly from one state to the other with no transition time.

  8. Joshua Schmidt

    May 23, 2011 - 6:22 am -

    Bowen, great idea with the basketball game! I hadn’t even thought about that.

  9. cheesemonkeysf

    May 23, 2011 - 6:46 am -

    Re #1: remember that in many of the non-California parts of the country, public swimming pools don’t even *OPEN* until Memorial Day.

    I just hate to see you disappointed in a predictable way.

    – Elizabeth (aka @cheesemonkeysf on Twitter)

  10. @Monty I was thinking the same thing. Gonna try it out on my road bike (has a cadence function to measure RPM).

    @Chris It’s a step function if you have constant speed.

  11. Bowen:

    Gear number is a step function, I think, although it’s an example a lot of students won’t understand because they’ve never driven a car – and some others would never have seen a stick shift!

    Dan A:

    It’s a step function if you have constant speed.

    I’m totally ready to be wrong here. But I don’t get what Bowen is imagining-what do you have on the x- and y-axis? I was imagining the original idea to be about going from 0 to 60, x-axis time, y-axis rpm. If that’s the idea, then it’s like the straw-continuous if abrubpt change.

    If I read Dan’s thought correctly, he has gear on x-axis; rpm on y-axis, with a constant (say 35 mph) speed. But that’s just a discrete set of points, right? I think of a step function as having a continuous domain.

  12. Mike Streeter

    May 23, 2011 - 8:44 am -

    @Bowen I can make the pinball machine idea happen. Father in law has an old machine in his basement. I’ll film it tonight and have my class graph it tomorrow.

  13. “remember that in many of the non-California parts of the country, public swimming pools don’t even *OPEN* until Memorial Day.”

    Remember that in many California parts of the country, public swimming pools don’t open at all, due to budget cuts. (Our city pool has been closed for two years–I think that they are renting it out to a private swim school this summer.)

  14. Chris D.

    It’s only continuous if you have gears as the x-axis. If you make the x-axis “derailleur travel” and the y-axis “rpm” then it is continuous.
    Maybe its a distinction without a difference, but I used to use bikes with analog shifters (instead of my current bike with pre-set jumps).

    Gonna try get video of it today if the weather holds off.

  15. @Daniel Sorry if I wasn’t clear about it: I mean for the time to be on the x-axis (as apparently required by all Graphing Stories… hmmm) and the gear number on the y-axis.

    Since the gear number is discrete (1-2-3-4-5) it must have discontinuity in its graph.

    I still like the kid-basketball or any other type of clear, discrete counter. Heck, maybe just the scoreboard during the top of the 8th of the Cubs-Red Sox game from last Saturday.

  16. I’ll do you one better than a carousel! One of my students made a video of herself riding a real horse. She is using distance from the ground to her shoulders. She trotted and walked with the horse, and then stood up in the stirrups to change up the elevation. She is uploading either tonight or tomorrow. (She just got an email address two months ago so she is new at much of the online stuff). It’s amazing. : )

    I have a swimmer – I’ll see if he would be interested in the diving board.

  17. I want to film do a time lapse of the London Eye turning round, and graph out the position over time and get a cycloid. I live in London, but am not sure where I can get a video camera from. Maybe there’s a video of that online already?

    Or Usain Bolt’s 100m dash? Did he really slow down at the end like everyone says he did?

  18. I was thinking the gear was a step function because it can only be N, R, 1, 2, 3, 4, or 5. It can’t be inbetween. Engine speed and ground speed will be continuous, but you could always go up to a specific RPM and hold it there before shifting. So I was envisioning the x axis as time, the y axis having three scales–speed, RPM, gear. The plot of the gear would be the step function.

  19. Someone swimming laps. The camera at one end of the pool as the person heads away from it and then back towards it. (In fifteen seconds.)

  20. Hi Sneha,

    Most people received theirs already (with one error that will be amended shortly). If you didn’t receive yours you should have received an email describing why. Either a) there was an error with your video or graph or b) your graph was non-standard (eg. different axes, multiple graphs, etc.) that will require extra time. I’m on the road but I’ll check on yours when I get home.

  21. Hi Dan,

    Still waiting for you to get home :-)
    I had got one email pointing out an error in the graph but I corrected that and got confirmation about it being okay. Was the video too long? I loved the exercise and would be really gratified to know where my step function got to………..

  22. Thanks for the question, Sneha. At this point my slate looks like this:

    1. Fix one error on the videos I’ve already made.
    2. Make the videos that were submitted with an error from the teacher. (Like yours.)
    3. Make the videos that were submitted with non-standard stuff like two graphs or weird-scaled axes.
    4. Get many of these videos online in a form that anyone can download.

    ETA October 2011 on the first three. Unknown ETA on the last one. Fun work, but time-consuming. No one’s been forgotten.

  23. When this was all live I wasn’t able to participate. I’m having a go now and having some success with some firsts for me – buying a flip camera, taking a video, using editing software etc. I’m also running in to some problems – how to add a timer and how to annotate over the video (i.e. draw a graph over the top).

    I was wondering what happened next with this project and if the videos were only made available to those who contributed.

  24. Hi! Are these accessible to the public? I looked on the website but didn’t see the completed videos. Thanks.

  25. Hey – I got mine after 6 months! but it was worth waiting for. Thanks Dan and I hope that the literal step function was useful. Happy to share with anyone who is interested. Would like comments

  26. @Eric, I’m looking at a folder full of 24 interesting, edited graphing stories. They’re ready to go, ready to use. All I need is a place to put them. My collaborators at Scolab will be setting up a site for them that’ll be ready somewhere by the end of the year.

  27. @Dan, do I have permission to use my edited graphing story on our Foundation’s portal ?

  28. I made one, got it back fixed up nicely with the graph and timer in an email. I saved the email but I can’t find where I saved the video. (I might not have downloaded it.) Now the link is broken. Is it still available somewhere???