[Rd] predict.lm is broken in 1.1.0-patched (2000-August-7) (PR#626)
ripley@stats.ox.ac.uk
ripley@stats.ox.ac.uk
Mon, 7 Aug 2000 20:43:38 +0200 (MET DST)
predict.lm has been broken by recent changes to the patched branch.
It fails for all singular fits. An example:
library(MASS)
data(quine)
quine.hi <- aov(log(Days + 2.5) ~ .^4, quine)
quine.nxt <- update(quine.hi, . ~ . - Eth:Sex:Age:Lrn)
predict(quine.nxt)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
141 142 143 144 145 146
NA NA NA NA NA NA
The answeer should be (e.g. R 1.1.0)
> predict(quine.nxt)
1 2 3 4 5 6 7 8
2.19247 2.19247 2.19247 2.68311 2.68311 2.68311 2.68311 2.68311
9 10 11 12 13 14 15 16
2.37260 2.37260 2.37260 2.53960 2.53960 3.53516 3.53516 3.53516
17 18 19 20 21 22 23 24
3.53516 3.24298 3.24298 3.24298 3.24298 3.24298 3.24298 3.24298
25 26 27 28 29 30 31 32
3.31368 3.31368 3.31368 3.31368 3.31368 3.31368 3.31368 2.03746
...
I believe this is a lot worse than that which the changes were intended to
fix. (Are we not supposed to be ultra-cautious about not making things
worse in that branch?)
--please do not edit the information below--
Version:
platform = sparc-sun-solaris2.6
arch = sparc
os = solaris2.6
system = sparc, solaris2.6
status Patched
major 1
minor 1.0
year 2000
month August
day 7
language R
Search Path:
.GlobalEnv, Autoloads, package:base
--
Brian D. Ripley, ripley@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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