Added dna_fraction_tests.R script

Author: aldomann

data-raw/dna_fraction_tests.R

@@ -0,0 +1,82 @@
+library(tidyverse)
+
+
+# Read data --------------------------------------------
+
+dna_table <- data.table::fread("shiny-app-bs4/libs/dna-content-fractions.csv")
+
+
+# Calculate fraction ---------------------------------------
+
+get_fraction <- function(dna_table, chromosome, color, sex) {
+  # Construct color/chromosome table
+  color_table <-
+    cbind(
+      color,
+      chromosome
+    ) %>%
+    as.data.frame() %>%
+    mutate(
+      chromosome = as.character(chromosome)
+    )
+
+  # Full table
+  full_table <- inner_join(color_table, dna_table, by = "chromosome") %>%
+    group_by(color) %>%
+    summarise(frac = sum(base::get(paste0("fraction_", sex))))
+
+  # Calculate first sum
+  single_sum <- full_table %>%
+    dplyr::select(frac) %>%
+    summarise(sum(frac * (1 - frac))) %>%
+    unname() %>%
+    unlist()
+
+  # Calculate second sum
+  if (nrow(full_table) >= 2) {
+    cross_sum <- full_table[["frac"]] %>%
+      combn(2) %>%
+      t() %>%
+      as.data.frame() %>%
+      summarise(sum(V1 * V2)) %>%
+      unname() %>%
+      unlist()
+  } else {
+    cross_sum <- 0
+  }
+
+  return(2 / 0.974 * (single_sum - cross_sum))
+}
+
+
+# Test function --------------------------------------------
+
+# From Excel sheet
+get_fraction(
+  dna_table,
+  c(1, 4),
+  c("red", "green"),
+  "male"
+)
+
+get_fraction(
+  dna_table,
+  c(1, 4),
+  c("red", "red"),
+  "male"
+)
+
+# From IAEA
+get_fraction(
+  dna_table,
+  c(1, 2, 4, 3, 5, 6),
+  c(rep("red", 3), rep("green", 3)),
+  "female"
+)
+
+get_fraction(
+  dna_table,
+  c(1, 2, 4),
+  c(rep("red", 3)),
+  "female"
+)