|You would not believe the fuss people make about graphs.
'They must be done in ink/pencil, must fill the (arbitrary) page, axes must be in ink and
the line in pencil...' - all the sorts of daft rules that teachers love.
is an art, which is why I don't let my students use computers to do it. Once they've
served their apprenticeship, fine, but not until then. The essentials in my scheme are
- the graph should be pleasantly proportioned; this means axes of equal length or in a
ratio of roughly 2:3, either landscape (page sideways on) or portrait (page normal);
- the axes should be ruled and have sensible divisions; this means each square is 1, 2, 5
or 10 units (or multiples or sub-multiples). Don't use 3 or 7 units per square! You will
mis-plot the points. Graphs take a long time for relatively small return, so make the
plotting as easy, therefore as fast as is possible.
- the points must remain visible once the line is drawn; use crosses, or dots with
circles, or if you know the error magnitudes, error bars;
BE CLEAR about the nature of your graph - does it represent a continuous
relationship needing a smooth curve, or a discontinuous one (e.g. something like
ionisation energy plotted against atomic number), where the lines joining the points
should be straight? Make sure you know before you join up the points.
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