This is Dataplot data file GRAYI617.DAT
Visual Response & Contrast Study
Source--Graybill & Iyer (1994). Regression Analysis:
Concepts and Applications, Duxbury, page 617.
Note--This data file GRA1617.DAT has equivalent contents
to the Grabill-Iyer data file CONTRAST.DAT
Response variable = proportion of times object seen (0 to 1)
Number of observations = 10
Number of variables per line image = 2
Order of variables on a line image--
1. Response variable = proportion of times object seen (0 to 1)
2. Factor 1 = foreground/background contrast
Statistical category--Regression (non-linear)
To read this file into Dataplot--
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READ GRAYI617.DAT Y X
Proportion Contrast
of Times Seen
----------------------------
.02 .000
.06 .005
.10 .010
.18 .015
.35 .020
.56 .025
.78 .030
.86 .035
.94 .040
.99 .045