BOXPLOT

class: center, middle, inverse, title-slide

# BOXPLOT
## explicando o boxplot
### Steven Ross
### UNIRIO
### 2019/12/12 (updated: 2020-05-04)

---

class: center, middle

body, td {
   font-size: 14px;
}
code.r{
  font-size: 10px;
}
pre {
  font-size: 20px
}
</style>

![](explicacao-boxplot_files/figure-html/unnamed-chunk-1-1.png)

---

```r
# Base curly brackets adapted from https://stackoverflow.com/a/9310002/5213091
CurlyBraces <- function(x, y, min.val,max.val, pos = 1, direction = 1 ,b=c(0,.2,.28,.7,.8),a=c(1,2,3,48,50)) {
  # a set flexion point for spline
  # b set depth for spline flexion point
  curve = spline(a, b, n = 50, method = "natural")$y / 2 
  curve = c(curve,rev(curve))
  a_sequence = rep(x,100)
  b_sequence = seq(min.val,max.val,length=100)  
  # direction
  if(direction==1)
    a_sequence = a_sequence+curve
  if(direction==2)
    a_sequence = a_sequence-curve
  # pos
  if(pos==1)
    lines(a_sequence,b_sequence) # vertical
  if(pos==2)
    lines(b_sequence,a_sequence) # horizontal
}
set.seed(1)
fake.dat=rnorm(1000)
x=boxplot(fake.dat,col="grey",pch=21,bg="black",axes=F,boxwex=0.3,xlim=c(0.5,2))
lines(c(1.07,1.3),rep(x$stats[1,],2),lty=2,col="grey75")
text(1.3,x$stats[1,],"Q1 - 1.5 x IQR",xpd=NA,pos=4,cex=0.75)
lines(c(1.07,1.3),rep(x$stats[2,],2),lty=2,col="grey75")
text(1.3,x$stats[2,],"Quantil 25 (Q1)",xpd=NA,pos=4,cex=0.75)
text(1.3,x$stats[3,],"Mediana",xpd=NA,pos=4,cex=0.75)
lines(c(1.07,1.3),rep(x$stats[3,],2),lty=2,col="grey75")
text(1.3,x$stats[4,],"Quantil 75 (Q3)",xpd=NA,pos=4,cex=0.75)
lines(c(1.07,1.3),rep(x$stats[4,],2),lty=2,col="grey75")
text(1.3,x$stats[5,],"Q3 + 1.5 x IQR",xpd=NA,pos=4,cex=0.75)
lines(c(1.07,1.3),rep(x$stats[5,],2),lty=2,col="grey75")
text(0.65,x$stats[2,]+diff(x$stats[c(2,4),])/2,srt=90,"Amplitude interquartil \n (Interquantile Range IQR)",adj=0.5,xpd=NA,cex=0.75)
CurlyBraces(0.9,x$stats[2,]+diff(x$stats[c(2,4),])/2,x$stats[2,],x$stats[4,],b=c(0,0.2,0.28,0.7,0.8)/7,direction=2)
CurlyBraces(1.1,mean(x$out[x$out>0]),min(x$out[x$out>0]),max(x$out[x$out>0]),
            b=c(0,0.2,0.28,0.7,0.8)/7,direction=1)
text(1.3,mean(x$out[x$out>0]),"Valor extremo",xpd=NA,cex=0.75,pos=4)
text(1.3,mean(x$out[x$out<0]),"Valor extremo",xpd=NA,cex=0.75,pos=4)
text(0.5,3.9,"Legenda",font=2,xpd=NA,cex=1.25)
```