graphinter function

Graphical display of the interaction between two qualitative variables

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

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 (product, panelist) and a set of quantitative variables (sensory descriptors)
• col.p: the position of one categorical variables of interest (the product variable)
• col.j: the position of one categorical variables of interest (the session variable)
• firstvar: the position of the first endogenous variable
• lastvar: the position of the last endogenous variable (by default the last column of donnee)
• 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).

Returns

If the variables of interest are the product and the session variables, a list containing the following components: - prod: a data frame of dimension (p,q), the means over the panelists and the sessions for the p products and the q sensory descriptors

• seance: as many matrices of dimension (p,q) as there are sessions, the means over the panelists for the p products, the q sensory descriptors and for each session

The graphical display of the interaction for each sensory descriptor.

References

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

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

Author(s)

F Husson, S Le

See Also

aov

Examples

## Not run:

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