# Graphical display of the interaction between two qualitative variables

### Description

This function is designed to display the interaction between two qualitative variables, in most cases
the *product* and the *session* variables.

### Usage

1 2 | ```
graphinter(donnee, col.p, col.j, firstvar, lastvar=ncol(donnee),
numr = 2,numc = 2)
``` |

### Arguments

`donnee` |
a data frame made up of at least two qualitative variables
( |

`col.p` |
the position of one categorical variables of interest (the |

`col.j` |
the position of one categorical variables of interest (the |

`firstvar` |
the position of the first endogenous variable |

`lastvar` |
the position of the last endogenous variable (by default the last column of |

`numr` |
the number of graphs per row (by default 2) |

`numc` |
the number of graphs per column (by default 2) |

### Details

The data set must be balanced (or not unbalanced too much).

### Value

If the variables of interest are the *product* and the *session* variables,
a list containing the following components:

`prod` |
a data frame of dimension ( |

`seance` |
as many matrices of dimension ( |

The graphical display of the interaction for each sensory descriptor.

### Author(s)

Fran<e7>ois Husson, S<e9>bastien L<ea>

### References

P. Lea, T. Naes, M. Rodbotten. *Analysis of variance for sensory data*.

H. Sahai, M. I. Ageel. *The analysis of variance*.

### See Also

`aov`

### Examples

1 2 3 4 5 6 | ```
## Not run:
data(chocolates)
graphinter(sensochoc, col.p = 4, col.j = 2, firstvar = 5, lastvar = 12,
numr = 1, numc = 1)
## End(Not run)
``` |