Re: [Phys-l] Graphing algebraic equations

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2010, Mar 22, , at 11:58, John Clement wrote:

> They frequently
> have students get data from graphs, and even present maps with tilted axes.


I've forgotten where I read this**.  It's a NO NO, furthermore, the writer wrote graphs must not have a grid.   The purpose of the graph is to illustrate the functional relationship.  If you want to further use the data, get it from the table.

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On 2010, Mar 22, , at 10:43, Marty Weiss wrote:

>  (They want to connect all the dots even though actual data often doesn't follow a pure curved pattern.  Then I bring out "Mimi and Fifi", my French curves, and teach them how to show a smooth best fit curve.  They have never seen a French Curve set before and probably never will, because when they go to the math class again they are right back to the calculators.  


I was taught not to connect the points, as this may be making a false assumption.  If one wants a curve, the data "rate" should be increased to the desired state.  In "my time" this usually would be ridiculous, but now w/ Vernier, et al, reasonable.  

> "... back to the calculators."

I suffered multiplication arrested development by my being given a circular slide rule.


**I did find:  Tufte writes ("The visual Display of Quantitative Info."  2nd ed.  p. 112 ff.):  grids are chart junk and should be muted if not dispensed with. (paraphrased)

bc guilty of drawing in a grid to extract data in the absence of a table.