7. GRAPHS

A graph consists of axes, and lines or points inside these axes sometimes called functions. Graphs being rather straightforward, they're excellent material for codifying, uniformity. So following the survey of adaptations I have written up a method for graphs.

Very simple graphs sometimes have arrows next to the axes: I think arrows don't mean much to our readers, so I put in a zero at the axes' intersection and leave out the arrows altogether.
Next to, or below the axes their meaning is often written in full: in particular at the y-axis this is often not a very clear indication (as I explained before) and besides it takes too much space, so I prefer to use an x and y at the axes in any graph, explaining their meaning in a key (years under the x-axis are fine). Only in case inkprint already has a one- or two-character identifier I copy those.

    Basic Graph
    inkprint (ca 35K)
    braille (ca 25K)
The small circle at the axes' intersection poses a Braille problem: is it number zero or capital letter O? In mathematics, to be recognized in inkprint by x and y at the axes, it's capital letter O; in all other graphs, showing real units at the axes, it's number zero.
Preferably put y and y-numbers left of y-axis, x and x-numbers below x- axis; but if this should impair the clarity of your drawing put them somewhere else.
In mathematics generally only the O and two 1's are shown: if possible, copy; otherwise put in some other number.
Sometimes a graph gets clearer by pruning axis numbers, there's often no need for the reader to go over a profusion of numbers.
In my opinion putting an identifying text or word next to a curve or function line is not very clear: you'd better choose different line types and explain their meaning in a key.
    Basic Math Graph
    wrong (ca 45K)
    better (ca 45K)
    Use Key
    inkprint (ca 35K)
    Braille (ca 35K)
The zeroes in the thousands or millions of the units at the axes unnecessary take space: cut down by explaining in key (e.g. "y - cars manufactured x1000").
In rare cases one of the rows of numbers might be written in a deviant direction. Preferably make a remark about this.

Draw the axes in a standard width, for instance 1mm.
Don't copy the zigzag indicating an axis interuption: a short break in the axis line (about 7mm, within the fingertip window) is clearer.

    Axis interruption (ca 35K)
In rendering grid, think of the reader who has to go over all these lines to take in your drawing. Ask yourself if grid is really necessary, is that much precision asked for? Sometimes one might just as well only draw lines from important points in the graph to the axes, so these values can be read accurately; in other cases just putting grid below or above the curve will do nicely.
    Remove Grid
    inkprint (ca 100K)
    Braille (ca 35K)
Replacing lines of fine grid by dots on the intersections, as already discussed in geometry, may clear up your drawing.
    Fine Grid (ca 65K)
A graph that has more than three or four function lines will generally have to be made into a series of graphs when the lines are too close together. Separate the close lines and try to have one of the lines, preferably a mean or reference line, in each graph of the series.
The function lines are the most important part of a graph, so have them stand out, draw them fat so they're easy to find.

If a graph has shadings between the lines we'll have to look for their meaning: sometimes it's just for decoration or sighted clarity and we can leave it out; in other cases the graph is all about the hatches' proportions, the shadings indicate volume, and we had better leave out the lines as they impair clarity.

    Shading in Graphs
    leave out (ca 60K)
    leave in (ca 80K)
    leave in #2 (ca 115K)
Except in mathematics there's no reason not to juggle x- and y-scales separately if the lines in your graph are close together. In Autocad this can be done by re-inserting a sketch of your graph as a block.

Look out for possibly confusing graphic elements, and simplify or relegate them to text. Estimates into the future are often dashed, in an otherwise continuous-line graph: copying this will unnecessarily complicate your drawing.
Reduce unusual graphs to the standard model.

    Split Up Complicated Graphs
    inkprint (ca 110K)
    Braille, part 1 (ca 65K)
    Braille, part 2 (ca 55K)
    Braille, part 3 (ca 50K)

METHOD

  1. Enlarge your original to desired size; if need be change x:y ratio
  2. Decide on the direction of your drawing: length- or widthwise?
  3. Will the graph leave enough space for your title (including key)? If so, put in page number and title; otherwise draw the graph first.
  4. Draw axes, 1mm width; put in x, y and 0, and dashes and numbers for units.
  5. Put in grid, possibly reduced.
  6. Put in function line or lines, curves. Decide on linetype by expediency (e.g. wriggling line thin, straight line fat).
  7. If so desired, put in referencing lines from important points in your lines to the axes (if no grid was applied).
  8. Reduce confusing elements

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© 1989, 2002 Marco Schuffelen All rights reserved

Questions? Comments? email me
Last modified: Thu May 15 10:32:53 PDT 1989