I am using the effects package to construct some probability graphs showing
the predicted probabilities from a logistic regression model.
However, I get an odd error message and don't know what the issue is.


When I attempt to generate the plots, I get the following error:

dat$won_ping = as.factor(dat$won_ping)

mod2 = glm(won_ping ~ our_bid +
  age_of_oldest_driver2 +
  credit_type2 +
  coverage_type2 +
  home_owner2 +
  vehicle_driver_score +
  currently_insured2 +
  zipcode2,
  data=dat, family=binomial(link="logit"))

> plot(effect("our_bid*home_owner2", mod2), rescale.axis=FALSE, multiline=TRUE)Warning message:In analyze.model(term, mod, xlevels, default.levels) :
  our_bid:home_owner2 does not appear in the modelError in
plot(effect("our_bid*home_owner2", mod2), rescale.axis = FALSE,  :
  error in evaluating the argument 'x' in selecting a method for
function 'plot': Error in apply(mod.matrix[, components], 1, prod) :
  subscript out of bounds



Here's info on my data and my glm commands:


> str(dat)'data.frame':	85240 obs. of  71 variables:
 $ our_bid                     : num  155 123 183 98 108 159 98 123 98 200 ...
 $ won_ping                    : Factor w/ 2 levels "0","1": 1 1 2 1 1
1 1 1 1 1 ...
 $ zipcode2                    : Factor w/ 4 levels
"1:6999","10000:14849",..: 4 3 2 1 3 2 3 1 2 2 ...
 $ age_of_oldest_driver2       : Factor w/ 4 levels "18 to 21","22 to
25",..: NA 3 NA NA NA NA 3 NA 3 NA ...
 $ currently_insured2          : Factor w/ 2 levels "0","1": 2 1 2 2 1
1 2 2 1 1 ...
 $ credit_type2                : Ord.factor w/ 4 levels
"POOR"<"FAIR"<..: 2 3 2 3 2 2 1 3 3 2 ...
 $ coverage_type2              : Factor w/ 4 levels
"BASIC","MINIMUM",..: 4 3 3 3 3 3 3 3 4 3 ...
 $ home_owner2                 : Factor w/ 2 levels "0","1": 1 2 2 2 2
2 2 2 2 2 ...
 $ vehicle_driver_score        : Factor w/ 2 levels "0","1": 1 1 1 1 1
1 1 1 1 1 ...



dat$won_ping = as.factor(dat$won_ping)

mod2 = glm(won_ping ~ our_bid +
  age_of_oldest_driver2 +
  credit_type2 +
  coverage_type2 +
  home_owner2 +
  vehicle_driver_score +
  currently_insured2 +
  zipcode2,
  data=dat, family=binomial(link="logit"))

summary(mod2)


And finally, here might be some useful info:

> sessionInfo()R version 2.14.0 (2011-10-31)
Platform: x86_64-pc-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United
States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United
States.1252

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets
methods   base

other attached packages:
[1] effects_2.2-1    colorspace_1.1-1 nnet_7.3-1       MASS_7.3-16
 lattice_0.20-0   foreign_0.8-46

loaded via a namespace (and not attached):
[1] tools_2.14.0



Thanks,
Abraham

























> sessionInfo()R version 2.14.0 (2011-10-31)
Platform: x86_64-pc-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United
States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United
States.1252

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets
methods   base

other attached packages:
[1] effects_2.2-1    colorspace_1.1-1 nnet_7.3-1       MASS_7.3-16
 lattice_0.20-0   foreign_0.8-46

loaded via a namespace (and not attached):
[1] tools_2.14.0














-- 
*Abraham Mathew
Statistical Analyst
www.amathew.com
720-648-0108
@abmathewks*

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