Add visualisation of mean in simulations

analysis/mean-dist-vis.Rmd

+---
+title: "Gamma distribution visualisation"
+output: html_document
+---
+
+```{r setup, include=FALSE}
+knitr::opts_chunk$set(echo = TRUE)
+```
+
+```{r libraries}
+library(splatter)
+library(ggplot2)
+```
+
+```{r sim-setup}
+set.seed(42)
+# Number of samples to make the histograms from.
+N <- 10000
+```
+
+```{r default-splat-params}
+default_params <- newSplatParams()
+default_params@mean.shape
+default_params@mean.rate
+```
+
+```{r default-params}
+default_params <- newSplatParams()
+shape <- default_params@mean.shape
+rate <- default_params@mean.rate
+
+data.frame(x = rgamma(N, shape = shape, rate = rate)) %>% 
+  ggplot(aes(x)) + 
+  geom_histogram(bins = 50) + 
+  labs(x = "Value", y = "Count") + 
+  theme_bw()
+
+shape
+rate
+shape / rate
+```
+
+```{r esimated-params}
+pbmc <- readRDS(here::here("data", "pbmc3k.rds"))
+est_params <- splatEstimate(as.matrix(logcounts(pbmc)))
+
+shape <- est_params@mean.shape
+rate <- est_params@mean.rate
+
+data.frame(x = rgamma(N, shape = shape, rate = rate)) %>% 
+  ggplot(aes(x)) + 
+  geom_histogram(bins = 50) + 
+  labs(x = "Value", y = "Count") + 
+  theme_bw()
+
+shape
+rate
+shape / rate
+```