> mean(c("-1","0", "1"))[1] NA Warning message: argument is not numeric or logical: returning NA in: mean.default(c("-1", "0", "1"))> median(c("-1","0", "1"))Error in median.default(c("-1", "0", "1")) : need numeric data> var(c("-1","0", "1"))[1] 1>Is the above intentional behavior? mean and median of character data give a warning and error. var gives the result of coercing the argument to numeric.