Gives methods to create a catenary object and then plot it and get properties of it. Can construct from parameters or endpoints. Also can get catenary fitted to data.
Correct fitCatEndPt function so do not get "if() with conditions of length greater than one" warning.
Updated so works with new version of ggplot2
catenary class with methods to plot and give properties
fittedCatenary class to create a catenary object from observed data