```
# NOT RUN {
# Not a good example for multinomial() because the response is ordinal!!
ii <- 3; hh <- 1/100
pneumo <- transform(pneumo, let = log(exposure.time))
fit <- vglm(cbind(normal, mild, severe) ~ let, multinomial, data = pneumo)
fit <- vglm(cbind(normal, mild, severe) ~ let,
cumulative(reverse = TRUE, parallel = TRUE),
data = pneumo)
fitted(fit)[ii, ]
mynewdata <- with(pneumo, data.frame(let = let[ii] + hh))
(newp <- predict(fit, newdata = mynewdata, type = "response"))
# Compare the difference. Should be the same as hh --> 0.
round(digits = 3, (newp-fitted(fit)[ii, ])/hh) # Finite-difference approxn
round(digits = 3, margeff(fit, subset = ii)["let",])
# Other examples
round(digits = 3, margeff(fit))
round(digits = 3, margeff(fit, subset = 2)["let",])
round(digits = 3, margeff(fit, subset = c(FALSE, TRUE))["let",,]) # recycling
round(digits = 3, margeff(fit, subset = c(2, 4, 6, 8))["let",,])
# }
```

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