ergograph

{{about||the muscle-measuring device|Mosso's ergograph}}

An ergograph is a graph that shows a relation between human activities and a seasonal year. The name was coined by Dr. Arthur Geddes of the University of Edinburgh. It can either be a polar coordinate (circular) or a cartesian coordinate (rectangular) graph, and either a line graph or a bar graph.{{cite book|title=Fundamentals of cartography|author=Rameshwar Prasad Misra and A. Ramesh|edition=2nd|publisher=Concept Publishing Company|date=1989| isbn=9788170222224 |pages=438}}{{cite encyclopaedia|encyclopedia=A Dictionary of Geography|author=Francis John Monkhouse|title=A Dictionary of Geography, Second Edition|edition=2nd|publisher=Aldine Transaction|date=2007| isbn=9780202361314 |pages=127}}

In polar form, the months of the year are marked around the circumference, forming 30° sectors. Concentric lines display the value being measured. For example an ergograph could show the proportions of time (in hours per day) devoted to each of certain activities, with a time scale, ranging from 0 to 24 hours per day, along the radius of the circle, as a square root scale. This form of an ergograph is an example of a polar line graph or (because the data form "bands" on the graph) a polar strata graph or polar layer graph, the "polar" denoting the system of polar coordinates used on the graph.{{cite book|title=Illustrations|author=Graham T. Richardson|publisher=Humana Press|date=1985| isbn=9780896030701 |pages=49–50}}

In cartesian form, the X axis is marked for the months of the year, and the Y axis is marked with the scale(s) of the activity/activities.