R: Data: Tensile Strength of Welds

welding {statmod} | R Documentation

## Data: Tensile Strength of Welds

### Description

This is a highly fractionated two-level factorial design employed as a screening design in an off-line welding experiment performed by the National Railway Corporation of Japan. There were 16 runs and 9 experimental factors. The response variable is the observed tensile strength of the weld, one of several quality characteristics measured. All other variables are at plus and minus levels.

### Usage

    data(welding)

### Format

A data frame containing the following variables. All the explanatory variables are numeric with two levels, `-1` and `1`.

| Variable | Description
| Rods | Kind of welding rods
| Drying | Period of drying
| Material | Welded material
| Thickness | Thickness
| Angle | Angle
| Opening | Opening
| Current | Current
| Method | Welding method
| Preheating | Preheating
| Strength | Tensile strength of the weld in kg/mm. The response variable.

### Source

http://www.statsci.org/data/general/welding.html

### References

Smyth, G. K., Huele, F., and Verbyla, A. P. (2001). Exact and approximate REML for heteroscedastic regression. Statistical Modelling 1, 161-175.

Smyth, G. K. (2002). An efficient algorithm for REML in heteroscedastic regression. Journal of Computational and Graphical Statistics 11, 1-12.

[Package statmod version 1.4.32 Index]