result_simulation-samplesize.rmd

---
title: "Simulation results for the causal discovery of DEGs"
author: "Yongjin Park"
---

```{r include = FALSE}
library(data.table)
library(patchwork)
library(tidyverse)
source("R/Util-rmd.R")
fig.dir = 'Fig/Simulation/size/'
dir.create(fig.dir, recursive = TRUE, showWarnings = FALSE)
knitr::opts_chunk$set(fig.path = fig.dir, results = "asis", message = FALSE)
knitr::opts_chunk$set(dev.args = list(bg = "transparent"))
options(stringsAsFactors = FALSE)
```

```{r helper_functions}
.fread <- function(x, ...) {
    .cmd <- ifelse(str_ends(x, "gz"), "gzip -cd ", "cat")
    fread(cmd = .cmd %&% " " %&% x %&% "| sed 's/  / NA /g'", ...)
}

.ggplot <- function(...) {

    ggplot(...) +
        theme_bw() +
        ggplot2::theme(plot.background = element_blank(),
                       plot.margin = unit(c(0,.5,0,.5), 'lines'),
                       strip.background = element_blank(),
                       strip.text = element_text(size=6),
                       legend.background = element_blank(),
                       legend.text = element_text(size = 8),
                       legend.title = element_text(size = 8),
                       axis.title = element_text(size = 8),
                       legend.key.width = unit(1, 'lines'),
                       legend.key.height = unit(.2, 'lines'),
                       legend.key.size = unit(1, 'lines'),
                       axis.line = element_line(color = 'gray20', size = .5),
                       axis.text = element_text(size = 6))
}
```

```{r read_simulation_v4_data}
.read.v4 <- function(hdr) {
    .files <- list.files(hdr %&% "/summary/",
                         pattern = "eval.gz", full.names=TRUE)

    .ct <- c("character","character","character",
             "character","character", "integer",
             "double","double","double",
             "double","double","double",
             "double","double","double",
             "double","double")

    .dat <- lapply(.files, .fread, header=TRUE, fill=TRUE,
                   colClasses = .ct)

    .dat <- .dat %>%
        do.call(what=rbind) %>%
        mutate(p1 = as.numeric("0." %&% p1)) %>%
        mutate(pa = as.numeric("0." %&% pa)) %>%
        mutate(pf = as.numeric("0." %&% pf)) %>%
        mutate(p0 = as.numeric("0." %&% p0))
}

.read.named.v4 <- function(x) {
    xx <-
        str_remove(x, "sim_v4_") %>%
        str_remove_all("[NMS]") %>%
        str_split("[_B]") %>%
        unlist %>%
        as.integer

    names(xx) <- c("N","M","S","B")
    ret <- .read.v4(x) %>% as.data.table
    ret[, N := xx[1]]
    ret[, M := xx[2]]
    ret[, S := xx[3]]
    ret[, B := xx[4]]
    return(ret)
}
```


```{r read_sim4_data}
.file <- ".simulation.v4.rdata"
if(!file.exists(.file)) {

    result.dt <-
        list.files(".", "sim_v4") %>%
        lapply(FUN=.read.named.v4) %>%
        do.call(what=rbind)

    save(list="result.dt", file=.file)
} else {
    load(.file)
}
result.dt[, p1.lab := "Variance Caused by Disease: " %&% (p1*100) %&% "%"]
result.dt[, nind := as.factor(N)]
result.dt[, ncell.per.ind := factor(M, c(50, 20), c(50, 20) %&% " cells per individual")]

.method <- c("cocoa", "mu", "avg", "tot", "MAST", "cf")
.method.lab <- c("CoCoA", "Bayesian", "Mean", "Total", "MAST", "Confounder")

result.dt[, method := factor(method, .method, .method.lab)]
```

# 1. Sample size

```{r}
plot.sample.size <- function(.dt) {

  .ggplot(.dt, aes(x = nind, y = auprc, fill=method)) +
    facet_grid(ncell.per.ind ~ p1.lab) +
    geom_boxplot(size=.3, outlier.size=0, outlier.stroke=0) +
    scale_fill_brewer("", palette = "Paired") +
    theme(legend.position = c(0, 1), legend.justification = c(0, 1)) +
    ylab("AUPRC") + xlab("Number of individuals")

}

#' Unconfounded simulation
plot.conf <- function(){
  .p0 <- .5
  .pf <- .0
  .dt <- result.dt[p1 > 0 & pf == .pf & p0 == .p0 & S == 5]
  return(plot.sample.size(.dt))
}

#' Violating ignorability assumption
plot.violating <- function(){
  .p0 <- .5
  .pf <- .1
  .dt <- result.dt[p1 > 0 & pf == .pf & p0 == .p0 & S == 5]
  return(plot.sample.size(.dt))
}
```

## When the disease label and other covariates are confounded and the conditional ignorability holds

```{r Fig_Size_Conf, fig.width=6, fig.height=4}
plt <- plot.conf()
print(plt)
.file <- fig.dir %&% "/Fig_Size_Conf.pdf"
.gg.save(.file, plot=plt, width=6, height=4)
```

## When the disease label and other covariates are confounded and the ignorability assumption breaks down

```{r Fig_Size_Viol, fig.width=6, fig.height=4}
plt <- plot.violating()
print(plt)
.file <- fig.dir %&% "/Fig_Size_Viol.pdf"
.gg.save(.file, plot=plt, width=6, height=4)
```