---
title: "EWMA chart"
author: ""
date: ""
output: html_document
---

## EWMA chart
Consider the piston ring data, and make EWMA charts for smoothing
parameter $\lambda=0.1,0.3,0.5$.

```{r message=FALSE}
library(qcc)
```

```{r eval=FALSE}
data(pistonrings)
diam    <- pistonrings$diameter
phaseI  <- matrix(diam[1:125],25,byrow=TRUE)
phaseII <- matrix(diam[126:200],15,byrow=TRUE)
data("pistonrings")
h1 <- ewma(phaseI, newdata = phaseII, lambda=..., title = "EWMA chart: pistonrings")
```