# Confidence ellipses around products based on panel descriptions

### Description

Comparison of panels.

### Usage

1 2 3 4 5 | ```
panelmatch(donnee, col.p, col.j, firstvar,
alpha = 0.05, coord = c(1,2), scale.unit = TRUE, nbsimul = 500,
nbchoix = NULL, centerbypanelist = TRUE,
scalebypanelist = FALSE, name.panelist = FALSE, cex = 1,
color = NULL, hierar = NULL)
``` |

### Arguments

`donnee` |
a list of data frames, each one made up of at least two qualitative variables
( |

`col.p` |
the position of the |

`col.j` |
the position of the |

`firstvar` |
the position of the first sensory descriptor (in each data frame, the same position) |

`alpha` |
the confidence level of the ellipses |

`coord` |
a length 2 vector specifying the components to plot |

`scale.unit` |
boolean, if T the descriptors are scaled to unit variance |

`nbsimul` |
the number of simulations (corresponding to the number of virtual panels) used to compute the ellipses |

`nbchoix` |
the number of panelists forming a virtual panel, by default the number of panelists in the original panel |

`centerbypanelist` |
boolean, if T center the data by panelist before the construction of the axes |

`scalebypanelist` |
boolean, if T scale the data by panelist before the construction of the axes (by default, FALSE is assigned to that parameter) |

`name.panelist` |
boolean, if T then the name of each panelist is displayed on the |

`cex` |
cf. function |

`color` |
a vector with the colors used; by default there are 35 colors defined |

`hierar` |
hierarchy in the variable (see |

### Value

A list containing the following elements:

`eig` |
a matrix with the component of the factor analysis (in row) and the eigenvalues, the inertia and the cumulative inertia for each component |

`coordinates` |
a list with: the coordinates of the products with respect to the panel and to each panelists
and the coordinates of the |

`hotelling` |
Returns a matrix with the P-values of the Hotelling's T2 tests for each pair of products: this matrix allows to find the product which are significatnly different for the 2-components sensory description |

Returns a graph of the products as well as a correlation circle of the descriptors.

Returns a graph where each product is displayed with respect to a panel and to each panelist composing
the panel; products described by the panel are displayed as square, they are displayed as circle when
they are described by each panelist.

Returns a graph where each product is circled by its confidence ellipse generated by virtual panels.
When a Multiple Factor Analysis is performed, returns a graph where each partial product is circled by its confidence ellipse generated by virtual panels.

### Author(s)

Fran<e7>ois Husson

### References

Husson F., Le Dien S. & Pag<e8>s J. (2005). Confidence ellipse for the sensory profiles obtained by Principal Components Analysis. *Food Quality and Preference*. 16 (3), 245-250.

Pag<e8>s J. & Husson F. (2005). Multiple Factor Analysis with confidence ellipses: a methodology to study the relationships between sensory and instrumental data. To be published in *Journal of Chemometrics*.

### See Also

`panellipse`

, `panellipse.session`

### Examples

1 2 3 4 5 6 7 8 | ```
## Not run:
data(chocolates)
Panel1=sensochoc[as.numeric(sensochoc[,1])<11,]
Panel2=sensochoc[as.numeric(sensochoc[,1])<21 & as.numeric(sensochoc[,1])>10,]
Panel3=sensochoc[as.numeric(sensochoc[,1])>20,]
res <- panelmatch(list(P1=Panel1,P2=Panel2,P3=Panel3), col.p = 4, col.j = 1, firstvar = 5)
## End(Not run)
``` |