需要引用Neget包 MathNet.Numerics
公式
[无偏常量 d2()、d3() 和 d4()](https://support.minitab.com/zh-cn/minitab/18/quality-and-process-improvement/control-charts/how-to/variables-charts-for-subgroups/i-mr-r-s-chart/methods-and-formulas/unbiasing-constants-d2-d3-and-d4/)
[无偏常量 c4() 和 c5()](https://support.minitab.com/zh-cn/minitab/18/quality-and-process-improvement/control-charts/how-to/variables-charts-for-subgroups/i-mr-r-s-chart/methods-and-formulas/unbiasing-constants-c4-and-c5/)
[无偏常量 c4'()](https://support.minitab.com/zh-cn/minitab/18/quality-and-process-improvement/control-charts/how-to/variables-charts-for-subgroups/i-mr-r-s-chart/methods-and-formulas/unbiasing-constant-c4/)
代码