Description Usage Arguments Details Value Author(s) See Also Examples

View source: R/anova_related.R

Analysis of variance with a count variable.

1 2 3 | ```
poisson.anova(y, ina, logged = FALSE)
geom.anova(y, ina, type = 1, logged = FALSE)
quasipoisson.anova(y, ina, logged = FALSE)
``` |

`y` |
A numerical vector with discrete valued data, i.e. counts. |

`ina` |
A numerical vector with discrete numbers starting from 1, i.e. 1, 2, 3, 4,... or a factor variable. This is suppose to be a categorical predictor. If you supply a continuous valued vector the function will obviously provide wrong results. |

`type` |
This argument is for the geometric distribution. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1. |

`logged` |
Should the p-values be returned (FALSE) or their logarithm (TRUE)? |

This is the analysis of variance with Poisson or geometric distributed data. What we do is a log-likelihood ratio
test. However, this is exactly the same as Poisson regression with a single predictor variable who happens to be
categorical. Needless to say that this is faster function than the glm command in R. For the same purpose with
a Bernoulli variable use `g2Test`

. The quasinpoisson.anova is when in the glm function you specify
family = quasipoisson. This is suitable for the case of over or under-dispersed data.

A vector with two values, the difference in the deviances (or the scale difference in the case of quasi poisson)
and the relevant p-value. The quasipoisson.anova also returns the estimate of the *φ* parameter.

Michail Tsagris

R implementation and documentation: Michail Tsagris <mtsagris@uoc.gr> and Manos Papadakis <papadakm95@gmail.com>.

```
logistic.cat1, g2Test, poisson.anovas, anova, poisson_only,
poisson.mle
```

1 2 3 4 5 6 7 8 9 10 11 | ```
y <- rpois(300, 10)
ina <- rbinom(300, 3, 0.5) + 1
a1 <- poisson.anova(y, ina)
a2 <- glm(y ~ ina, poisson)
## Not run:
res<-anova(a2, test = "Chisq")
## End(Not run)
y <- rgeom(300, 0.7)
res<-geom.anova(y, ina)
``` |

```
Loading required package: Rcpp
Loading required package: RcppZiggurat
```

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