Monthly Archives: September 2012

‘Equal Aspect’ in Autograph

“I am drawing some quadratic functions to get some graphs for a flipchart. I go to Axes => Edit Axes, and set my Ranges. Autograph seems happy with my range, but it doesn’t seem to like my domain, so it changes it. eg I chose an x-range from -3 to 5, but Autograph gives me a range of -7 to 18.

‘Equal Aspect’ is a mode in Autograph, ensuring that the x- and y- scales are the same. When it is ON, the line y=x will always be at 45° and a circle will always be circular, regardless of the aspect of the graphing window.  Autograph achieves an equal aspect by adjusting the ‘x’ scale to fit the ‘y’ scale. So when it is ON, in ‘Edit Axes’ there is not much point in entering values for ‘x’, though the domain entered will have an influence on the positioning of the origin.

‘Equal Aspect’ is ON by default in the Standard Level. Illustrated here is a quadratic graph with ‘Equal Aspect’ ON and OFF, but with the same ‘y’-range.  Also drawn is a tangent and normal at x = 2, and a circle centre (2,2) and radus 4. To obtain this screenshot I had just two pages open and used the feature Window => ‘Tile Vertical’.

Autograph files (.agg):  Equal Aspect ON  –  Equal Aspect OFF