rankits(x [,ties:"ignore" or "average" or "minimum"]), x REAL or a structure with REAL components. rankits(n:N), integer N > 0 |

rankits(x) computes the vector of rankits (normal scores) for data in REAL vector x. rankits(n:N), N a positive integer, is equivalent to rankits(run(N)). An important use is plot(rankits(x),x) which produces a rankit or normal scores plot of the values in x. What is computed is equivalent to invnor((rank(x,ties:"ignore") - .375)/(n + .25)) where n is the number of non-MISSING values. The value corresponding to a MISSING value is MISSING. rankits(x [keywords]) has the same labels as x, if any. rankits(x,ties:method), where method is "ignore", "average", or "minimum" (or "i", "a", "m") computes invnor((rank(x,ties:method) - .375)/(n + .25)) See rank() for a detailed discussion of the three methods. It is hard to think of a situation when you would want to use "minimum" with rankits(). When x is a matrix, the result is a matrix each of whose columns contains the rankits for the corresponding column of x. When x is an array, rankits(x) is an array of the same size and shape with all the elements with fixed values of subscripts 2, 3, ... defining a "column" whose rankits are computed. An array with dimension > 2 is always treated as an array and not as a matrix, even if there are at most two dimensions greater than 1. It is also acceptable for x to be a structure, whose non-structure components are all REAL. In that case, rankits() returns a structure of the same form, each of whose non-structure components is the result of applying rankits() to the corresponding component of x. Cmd> x <- vector(10.59,18.82,19.46,13.34,13.49)#ranks are 1,4,5,2,3 Cmd> rankits(x) (1) -1.1798 0.4972 1.1798 -0.4972 0 See also halfnorm().

Gary Oehlert 2003-01-15