11 Replies Latest reply: Apr 27, 2012 6:26 AM by Papa.G
AstroMacMan Level 2 Level 2 (295 points)

I had a few moments to play around with Numbers on an iPad today and it did not seem have this ability.  Did I simply overlook the option?

 

It's such a basic chart type that I was quite surprised.  I even tried it on a MacBook Air and couldn't find it in the desktop/laptop version either!


iPad, iOS 5.0.1, Wonderful, magical device!
  • Papa.G Level 1 Level 1 (25 points)

    If this is what you are calling an x-y scatter plot, then

    from the Charts menu, it's the one with all the little random dots.

     

    Untitled-1.jpg

    An example: x vs ln(x).

  • AstroMacMan Level 2 Level 2 (295 points)

    That's a nice function plot!  Didn't know it could do that.

     

    I'm looking at plotting one variable vs. another.  For example, suppose you plot country GDP vs. Poverty.  Here's some made up data.

     

    Country     GDP     Poverty

    U.S.            340     .20

    France        190     .16

    Germany     280     .09

    China          165     .45

     

    It should produce a plot such as this, ordered by variable magnitude

     

    Screen shot 2012-03-19 at 1.30.14 PM.png

     

    rather than this, ordered by the original sequence, with equal spacing between points.

     

    Screen shot 2012-03-19 at 1.30.21 PM.png

  • Papa.G Level 1 Level 1 (25 points)

    This is what I get using the scatter plot in Numbers:

     

    pov.jpg

  • AstroMacMan Level 2 Level 2 (295 points)

    Great to read and see--and thank you for running the data through it!

     

    I'll have to go back to the store and explore Numbers again.  When I tried it before, my first graphing tries couldn't do it!  User-error likely!

  • Papa.G Level 1 Level 1 (25 points)

    Well, I can't say much for the documentation. I mainly just fiddle with it until I figure it out. Good luck! :-D

  • AstroMacMan Level 2 Level 2 (295 points)

    Ah, that's good!  I tested this again and discovered that the scatterplot chart choice was below the icons displayed-- it's off the screen!  And without scroll bars, there's no way of knowing that there's another choice there.  (That's on an iPad; I'm soon going to check out Numbers on the Mac, too.)

     

    However, I've discovered another major limitation for my work.  It does NOT seem able to do what Excel calls line scatterplots or what others would call trend lines.

     

    That is, you have a sequence of data ordered by non-consecutive years, e.g.,

     

    1912      140

    1922      195

    1938      260

    1945      480

     

    What it seems to produce in such cases is a ranked sequence--by point 1, point 2, point 3, etc. with equal spacing.  In other words, it can do a line chart, with even spacing between the x-axis years... which, of course, isn't what one has in that data!   The x-axis points should differ by 10 years, then 16, and then 7.

     

    It's the same problem in Excel if you simply select line chart rather than scatter plot for such data, the data aren't displayed properly (you actually need to choose the scatter plot with lines to show the trend line).

     

    Much historical data takes that form... where there hasn't been annual data gathering, but rather intermittent surveys.

     

    Any ideas, Papa G.??  (Or, anyone else?!!)  I have again overlooked a choice in Numbers?  Or, an obvious work around?

     

    If my verbiage isn't clear, I can post two comparative graphs showing what I mean!  Thanks for any and all input!

  • Papa.G Level 1 Level 1 (25 points)

    Maybe I'm not getting what you are asking. When I plot your example data, using the scatter plot, I get:

    Untitled-1.gif

    Is this not what you were expecting?

  • AstroMacMan Level 2 Level 2 (295 points)

    Yes, that's it, but with the points connected by a line!   In other words, a trend line.  It's a pretty standard graph used in social science and applied research--shows up in reports all the time and even in business presentations--for example, sales trends, where the units or $ points over time are connected by a line, revealing whether things are going up or down-- or, getting worse or better.

     

     

     

    Excel calls this a "Straight Marked Scatter".  It's the first of their x-y scatterplots in the Chart Gallery. 

     

     

     

    Here's an example from a federal report on reading achievement trends (it's in the public domain).   It just happens to show how little improvement there's been in reading in spite of a generation of testing, accountability, and standards school reform efforts!

     

    NAEP Reading Trends.png

     

    Thanks for your continued exploration and feedback on this!  It's appreciated!

  • Papa.G Level 1 Level 1 (25 points)

    Untitled-1.gif

     

    lol, just select Connect Points in the Numbers Chart menu.

  • AstroMacMan Level 2 Level 2 (295 points)

    Brilliant!  I appreciate both your helpfulness and sense of humor!

     

    I think I even read that you can choose between curved and straight line connections.

     

    While I have Docs 2 Go, it doesn't seem to do charts and its approach to cell handling is counter-intuitive.   I remember being wowed by the introduction of Numbers at an Apple keynote...  the connected scatter plotting was holding me back.  But no longer-- and much thanks to you!

     

    When I get through with my research and writing today, I'm going to treat myself to Numbers for iOS.  It'll be great fun and a reward for hard work.

  • Papa.G Level 1 Level 1 (25 points)

    I'm glad I was able to help! The documentation for Numbers is pretty lean. You just have to dig through it and try all the options. Have fun and good luck with your projects!