This function is meant as a userfriendly wrapper to approximate the way logistic regression is done in SPSS.

```
logRegr(formula,
data = NULL,
conf.level = 0.95,
digits = 2,
pvalueDigits = 3,
crossTabs = TRUE,
plot = FALSE,
collinearity = FALSE,
env = parent.frame(),
predictionColor = viridis(3)[3],
predictionAlpha = 0.5,
predictionSize = 2,
dataColor = viridis(3)[1],
dataAlpha = 0.33,
dataSize = 2,
observedMeansColor = viridis(3)[2],
binObservedMeans = 7,
observedMeansSize = 2,
observedMeansWidth = NULL,
observedMeansAlpha = 0.5,
theme = theme_bw())
```

formula

The formula, specified in the same way as for `glm`

(which is used for the actual analysis).

data

Optionally, a dataset containing the variables in the formula (if not specified, the variables must exist in the environment specified in `env`

.

conf.level

The confidence level for the confidence intervals.

digits

The number of digits used when printing the results.

pvalueDigits

The number of digits used when printing the p-values.

crossTabs

Whether to show cross tabulations of the correct predictions for the null model and the tested model, as well as the percentage of correct predictions.

plot

Whether to display the plot.

collinearity

Whether to show collinearity diagnostics.

env

If no dataframe is specified in `data`

, use this argument to specify the environment holding the variables in the formula.

predictionColor, dataColor, observedMeansColor

The color of, respectively, the line and confidence interval showing the prediction; the points representing the observed data points; and the means based on the observed data.

predictionAlpha, dataAlpha, observedMeansAlpha

The alpha of, respectively, the confidence interval of the prediction; the points representing the observed data points; and the means based on the observed data (set to 0 to hide an element).

predictionSize, dataSize, observedMeansSize

The size of, respectively, the line of the prediction; the points representing the observed data points; and the means based on the observed data (set to 0 to hide an element).

binObservedMeans

Whether to bin the observed means; either FALSE or a single numeric value specifying the number of bins.

observedMeansWidth

The width of the lines of the observed means. If not specified (i.e. `NULL`

), this is computed automatically and set to the length of the shortest interval between two successive points in the predictor data series (found using `findShortestInterval`

.

theme

The theme used to display the plot.

Mainly, this function prints its results, but it also returns them in an object containing three lists:

The arguments specified when calling the function

Intermediat objects and values

The results, such as the plot, the cross tables, and the coefficients.

This function

`regr`

and `fanova`

for similar functions for linear regression and analysis of variance and `glm`

for the regular interface for logistic regression.

```
# NOT RUN {
### Simplest way to call logRegr
logRegr(data=mtcars, formula = vs ~ mpg);
### Also ordering a plot
logRegr(data=mtcars, formula = vs ~ mpg, plot=TRUE);
### Only use five bins
logRegr(data=mtcars, formula = vs ~ mpg, plot=TRUE, binObservedMeans=5);
# }
```

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