19
$\begingroup$

My ODEs textbook uses both graph and plot but I can't figure out how it chooses one over the other.

From the book:

Sketch the graph of the solution in the x1x2-plane for t ≥ 0.
[this one was referring to a continuous function]

Also from the book:

Plots of the solution and a tangent line approximation for the initial value problem (11).
[this one referring to a continuous solution]

Is there a formal, to some degree, distinction between the two terms? When do I call it a plot and when do I call it a graph?

  • 7
    ...In all of my math classes (I'm a math major), we talk about plotting points, but we graph functions. You can plot specific points in the graph of a function, but you don't just plot a function. Generally, plot, as a noun, refers to a set of points that may or may not be connected by a line, but that cannot be represented as a function. I don't know if there's some technical ground behind this, but if there is, one of us is being confused...2011-03-28
  • 0
    So you're saying plotting is discrete and graphing is continuous? (or at least piecewise continuous?)2011-03-28
  • 0
    That's my impression, but I have nothing to back it up except my own observations, which is why I left a comment instead of an answer.2011-03-28
  • 1
    There used to be graphics printers called *line plotters* which joined lines. *Graph* just means *draw* (as a verb) and I would take it to be more general than *plot*.2011-03-28
  • 0
    I just checked my ODEs book and it labels a "plot" of a sine wave. (which is continuous) Interestingly, it asks you to "sketch the graph of..." a continuous function. The book uses both terms in similar ways but I can't figure out how it chooses one over the other.2011-03-29
  • 0
    Also "figure", and occasionally "chart". Special case: "histogram" (used a lot in particle physics to mean a generic plot because of the (pernicious?) influence of [PAW](http://paw.web.cern.ch/paw/) and [Root](http://root.cern.ch/drupal/)).2011-03-29
  • 0
    There are so many other definitions of 'plot' and 'graph' that do not overlap, that it is hard to think of them as synonymous.2011-03-29
  • 0
    I don't really think they're synonymous. I'm just trying to figure out when to use one over the other.2011-03-29
  • 0
    @kitukwfyer, you should make it an official answer. This is the right difference. This is why electronic point printers are also called plotters. See also a plot of land: a small surface, a spot. You draw a graph from mathematical analysis and for empirical functions, you measure or compute points and you plot them.2011-03-29
  • 0
    @kitukwfyer - I'm only a physicist but we say plot, as in "plot y as a function of x" - in fact I can't think of when I would use graph as a verb. It might also be a UK/US thing?2011-03-29
  • 0
    @mgb: It's possible. I would understand "plot y as a function of x," but it sounds a little funny to me. I would use "graph" there preferentially. Still, I would understand it. It could also be a math/physics thing. My calc III professor never tires of warning us about the inherent dangers of using physicists' notation. XP I'm sure he'd be happy to extend it to language. :)2011-03-29
  • 0
    @kitukwfyer - come over to the dark side, we have cooler toys!2011-03-29
  • 0
    This has been migrated to Math as requested by the OP himself.2011-04-05
  • 0
    @RegDwight: awesome - thank you!2011-04-05
  • 0
    see also: "chart"2015-04-30

5 Answers 5