## ----echo=FALSE---------------------------------------------------------------
knitr::include_graphics("figs/f1_digital.png", dpi=200)

## ----echo=FALSE---------------------------------------------------------------
knitr::include_graphics("figs/f2_digital.png", dpi=200)

## ----echo=FALSE---------------------------------------------------------------
knitr::include_graphics("figs/f3_digital.png", dpi=200)

## ----echo=FALSE---------------------------------------------------------------
knitr::include_graphics("figs/f4_digital.png",dpi = 200)