Can anybody suggest a software other than Ternary plotting that enables me to evaluate variance similarity between three oxides and/or elements as variables from data sets that have visually identical characteristics, e.g., cobalt blue glass from Egypt and/or Mesopotamia may look the same and may exhibit close to equal uniformity in their production but could differ in the oxides and/or elements that create the blue colouration? I am able to do most of the analysis using PCA but generally can only represent my results in X, Y plots, e.g., PC1 and PC2. I can use ternary plotting for approximate representation, however, this can only be done by setting the three variables adding up to 100% for each variable set, somewhat compromising the results in my opinion. I generally use PAST325 software but am interested if anybody knows of an affordable alternative that will display three separate eigenvalues for example?