# Articles by R on Thomas Roh

### PE Industrial Engineer Reference Sheet

May 8, 2018 |

You contribute to the reference sheet here: https://github.com/tomroh/pe_ise_prep. Systems Definition, Analysis, and Design System Analysis and Design Tools Cause-Effect Diagram (Fishbone) Pareto Analysis 80% of the items represent 20% of the sales or 20% of the items represent 80% of the cost. This law is a rule of ... ### fitur 0.5.25 Release

March 13, 2018 |

Fixed appearance of plots Added plot_density function for comparison pdfs of fitted functions Updated argument naming conventions fitur on CRAN Density Diagnostic Plot
library(fitur)
library(ggplot2)
library(trstyles)
set.seed(37)
x <- rgamma(10000, 5)
dists <- c('gamma', 'lnorm', 'weibull')
fits <- lapply(dists, fit_univariate, x = x)
theme_set(theme_tr())
plot_density(x, fits, nbins = 20)
QQ-Plot The output is a ggplot object so you can add colors, styling, etc.
plot_pp(x, fits) +
scale_color_tr()
PP-Plot You can also zoom in on different areas.
plot_qq(x, fits) +
scale_color_tr() +
coord_cartesian(xlim = c(5,10)) ### Statistical Distribution Tables

March 9, 2018 |

$$\text{Normal Distribution}$$ Table 2: Cumulative Probabilities of the Standard Normal Distribution, $$X \sim N(0,1)$$ z 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.0 0.5000 0.5040 0.5080 0.5120 0.5160 ... ### Building Distribution Reference Tables in R

March 9, 2018 |

I’ve recently been studing for a professional exam that does not allow computers or advanced calculators. Some of the subject matter will require use of a few statistical distributions which can be very time-consuming to calculate manually. In lieu of access to statistical functions, you are allowed to bring ... ### Queueing Notation

January 12, 2018 |

Queueing theory has some commonly accepted shorthand to describe characteristics of queuing models. Although across books and peer reviewed articles you will see slight variations, this post outlines commonly accepted terms for reference. Kendall’s Notation Kendall’s notation was proposed as a standard for describing queueing models. You may ... ### fitur 0.5.20 Release

December 19, 2017 |

DESCRIPTION summary has been updated Examples have been updated for fit_univariate, fit_empirical fit_empirical_discrete and fit_empirical_continuous are no longer exported added plot_qq and plot_pp functions for diagnostic plotting of fits Added ... [Read more...]

### MMC Queues

December 2, 2017 |

Introduction Queueing Theory is the quantitative study of operational characteristics of a system of workflows for a service/process given a processing time, an arrival pattern, and a limitation of resources. It can answer questions such as: How long would a customer/part/etc. (entities) wait to be processed? What ... [Read more...]
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