
SHIFT PLOTName:
with y_{q} and x_{q} denoting the qth quantiles of y and x, respectively. Although this plot can be generated for any pair of variables, the primary usage of this plot is for the case where x is a control group and y is an experimental method. Alternatively, x could represent an "old" method while y represents a "new" method. The plot measures how much the control group must be shifted so that it is comparable to the expermimental method (relative to the quantiles). The quantiles of a distribution are the distribution's "percent points" (e.g., the 0.5 quantile = the 50% point = the median). The plot consists of the following:
Horizontal axis = estimated quantiles from data set 2. The shift plot is a variation of the quantilequantile plot and the Tukey meandifference plot.
where <y> is the response variable for the experimental group; <x> is the response variable for the control group; and where the <SUBSET/EXCEPT/FOR qualification> is optional. With this syntax, the quantiles correspond to the data points of the <x> variable.
where <y> is the response variable for the experimental group; <x> is the response variable for the control group; <q> is a variable (with values between 0 and 1) that specifies the desired quantiles to plot; and where the <SUBSET/EXCEPT/FOR qualification> is optional. With this syntax, you explicitly give the desired quantiles.
SHIFT PLOT Y X SUBSET X > 1 SHIFT PLOT Y X XQ SHIFT PLOT Y X XQ SUBSET X > 1
SKIP 25 READ AUTO83B.DAT Y1 Y2 . DELETE Y2 SUBSET Y2 < 0 LABEL CASE ASIS Y1LABEL Difference between Y1 and Y2 Quantiles X1LABEL Quantiles for Y2 CHARACTER X LINE BLANK SHIFT PLOT Y1 Y2
 
Date created: 02/28/2003 Last updated: 12/04/2023 Please email comments on this WWW page to alan.heckert@nist.gov. 