Table of Control Chart Constants d2, d3, and c4

Build a matrix with the constants \(d_2\), \(d_3\), and \(c_4\) for sample sizes \(n = 2, 3, \ldots,\) the specified maximum.

Usage

table.const(n)

Arguments

n: Maximum sample size (must be \(\ge 2\)). The table includes rows for \(n = 2, 3, \ldots, n\).

Value

A matrix with \(n - 1\) rows and 3 columns named "d2", "d3", "c4". Row names are the sample sizes.

Details

The three constants are those returned by d2, d3, and c4 respectively. They are the standard Shewhart chart constants for the relative range and the standard deviation under normality.

Errors

Stops if n < 2, raised by the internal d2 call.

References

Montgomery, D. C. (2009). Introduction to Statistical Quality Control, 6th ed. Wiley.

Author

Daniela R. Recchia, Emanuel P. Barbosa

Examples


table.const(10)
#>          d2        d3        c4
#> 2  1.128379 0.8525025 0.7978846
#> 3  1.692569 0.8883680 0.8862269
#> 4  2.058751 0.8798082 0.9213177
#> 5  2.325929 0.8640819 0.9399856
#> 6  2.534413 0.8480397 0.9515329
#> 7  2.704357 0.8332053 0.9593688
#> 8  2.847201 0.8198311 0.9650305
#> 9  2.970026 0.8078343 0.9693107
#> 10 3.077505 0.7970507 0.9726593
table.const(5)
#>         d2        d3        c4
#> 2 1.128379 0.8525025 0.7978846
#> 3 1.692569 0.8883680 0.8862269
#> 4 2.058751 0.8798082 0.9213177
#> 5 2.325929 0.8640819 0.9399856