Hi, I am trying to calculate a distance matrix on a binary data frame using dist.binary() {ade4}. This is the code I run and the error I get: > sjlc.dist <- dist.binary(as.data.frame(data), method=2) #D = (a+d) / (a+b+c+d) Error in if (any(df < 0)) stop("non negative value expected in df") : missing value where TRUE/FALSE needed I don't know if the problem are the missing values in my data. If so how can I handle them? Thank you, Marc.