pulpfiber {robustbase} | R Documentation

## Pulp Fiber and Paper Data

### Description

Measurements of aspects pulp fibers and the paper produced from them. Four properties of each are measured in sixty-two samples.

### Usage

    data(pulpfiber)

### Format

A data frame with 62 observations on the following 8 variables.

`X1`

  numeric vector of arithmetic fiber length

`X2`

  numeric vector of long fiber fraction

`X3`

  numeric vector of fine fiber fraction

`X4`

  numeric vector of zero span tensile

`Y1`

  numeric vector of breaking length

`Y2`

  numeric vector of elastic modulus

`Y3`

  numeric vector of stress at failure

`Y4`

  numeric vector of burst strength

### Details

Cited from the reference article: The dataset contains measurements of properties of pulp fibers and the paper made from them. The aim is to investigate relations between pulp fiber properties and the resulting paper properties. The dataset contains n = 62 measurements of the following four pulp fiber characteristics: arithmetic fiber length, long fiber fraction, fine fiber fraction, and zero span tensile. The four paper properties that have been measured are breaking length, elastic modulus, stress at failure, and burst strength.

The goal is to predict the q = 4 paper properties from the p = 4 fiber characteristics.

### Author(s)

port to R and this help page: Martin Maechler

### Source

Rousseeuw, P. J., Van Aelst, S., Van Driessen, K., and Agulló, J. (2004) Robust multivariate regression; Technometrics 46, 293–305.

Till 2016 available from `http://users.ugent.be/~svaelst/data/pulpfiber.txt`

### References

Lee, J. (1992) Relationships Between Properties of Pulp-Fibre and Paper, unpublished doctoral thesis, U. Toronto, Faculty of Forestry.

### Examples

    data(pulpfiber)
    str(pulpfiber)

    pairs(pulpfiber, gap=.1)
    ## 2 blocks of 4 ..
    c1 <- cov(pulpfiber)
    cR <- covMcd(pulpfiber)
    ## how different are they: The robust estimate has more clear high correlations:
    symnum(cov2cor(c1))
    symnum(cov2cor(cR$cov))

[Package robustbase version 0.92-8 Index]