If I have a data set with 6 variables (A, B, C, D) all measured in different units (eg. m, kg, s, K) and I perform principal component analysis to transform this into two Principal Axes, how do I express the units of those axes?
For example: PC1= aA[m] + bB[s] + cC[K] + dD[kg] (a,b,c,d are constants from the eigenvectors)
What are the units of PC1? Does it even make sense to give this a unit? Can I relate it to some physical aspect of the system or is it too abstract?