 In an analysis where "X" and "Y" are treated symmetrically, the log-ratio log("X" / "Y") is zero in the case of equality, and it has the property that if "X" is "K" times greater than "Y", the log-ratio is the equidistant from zero as in the situation where "Y" is "K" times greater than "X" (the log-ratios are log("K") and −log("K") in these two situations).If values are naturally restricted to be in the range 0 to 1, not including the end-points, then a logit transformation may be appropriate