add LTR and BIC

src/clustering.Rmd

@@ -49,8 +49,7 @@ test_slope(1.05, 2.05, 0.95)
 Simulate k-mer counts data
 
 ```{r}
-n_kmer = 1e2
-mean_coef = 1000
+sim_kmer <- function(n_kmer, mean_coef, sex = "XY") {
     data <- tibble(
         sex = "F",
         count = mvtnorm::rmvnorm(n_kmer * .1, mean = c(1, 2)*mean_coef, sigma = matrix(c(1.05, 2, 2, 4.05) * mean_coef^1.5, ncol = 2), checkSymmetry = F, method = "svd") %>%
@@ -58,21 +57,28 @@ data <- tibble(
     ) %>%
         unnest(count) %>% 
         bind_rows(
-        tibble(
-            sex = "M",
-            count = mvtnorm::rmvnorm(n_kmer * .05, mean = c(1, 0)*mean_coef, sigma = matrix(c(.9, .05, .05, .05) * mean_coef^1.5, ncol = 2), method = "svd")
-            %>% as_tibble()
-        ) %>%
-        unnest(count)
-    ) %>% bind_rows(
             tibble(
                 sex = "A",
                 count = mvtnorm::rmvnorm(n_kmer * 0.85, mean = c(2, 2)*mean_coef, sigma = matrix(c(1, .95, .95, 1) * mean_coef^1.5 * 4, ncol = 2), method = "svd")
                 %>% as_tibble()
             ) %>% unnest(count)
+        )
+    if (sex == "XY") {
+        data <- data %>% 
+            bind_rows(
+                tibble(
+                    sex = "M",
+                    count = mvtnorm::rmvnorm(n_kmer * .05, mean = c(1, 0)*mean_coef, sigma = matrix(c(.9, .05, .05, .05) * mean_coef^1.5, ncol = 2), method = "svd")
+                    %>% as_tibble()
                 ) %>%
+                unnest(count)
+            )
+    }
+    data %>% 
         rename(count_m = V1,
                count_f = V2)
+}
+data <- sim_kmer(1e4, 1000, "XY")
 data %>% 
     ggplot(aes(x = count_m, y = count_f, color = sex)) +
     geom_point() +
@@ -123,15 +129,6 @@ params_diff <- function(old_theta, theta, threshold) {
     return(T)
 }
 
-proba_total <- function(x, theta, cluster_coef, sex) {
-    proba <- 0
-    for (params in expand_theta(theta, cluster_coef, sex)) {
-        proba <- proba + params$pi * 
-            mvtnorm::dmvnorm(x, mean = params$mu, sigma = params$sigma)
-    }
-    return(proba)
-}
-
 proba_point <- function(x, theta, cluster_coef, sex) {
     proba <- c()
     for (params in expand_theta(theta, cluster_coef, sex)) {
@@ -143,7 +140,7 @@ proba_point <- function(x, theta, cluster_coef, sex) {
 }
 
 loglik <- function(x, theta, cluster_coef, sex) {
-    -log(sum(proba_total(x, theta, cluster_coef, sex)))
+    sum(log(rowSums(proba_point(x, theta, cluster_coef, sex))))
 }
 
 # EM function
@@ -243,8 +240,16 @@ init_param <- function(x, sex) {
     return(list(cluster_coef = cluster_coef, theta = theta))
 }
 
+compute_bic <- function(x, loglik, sex = "XY") {
+    k <- 1 + 4 * 2
+    if (sex == "YX") {
+        k <- k + 4
+    }
+    return(k * log(nrow(x)) - 2 * loglik)
+}
+
 
-EM_clust <- function(x, threshold = 0.1, sex = "XY") {
+EM_clust <- function(x, threshold = 1, sex = "XY") {
     old_loglik <- -Inf
     new_loglik <- 0
     param <- init_param(x, sex)
@@ -256,53 +261,80 @@ EM_clust <- function(x, threshold = 0.1, sex = "XY") {
         param$theta$sigma <- M_cov(x, proba, param$theta$mu, param$theta$pi, param$cluster_coef, sex)
         param$theta$pi <- param$theta$pi / nrow(x)
         new_loglik <- loglik(x, param$theta, param$cluster_coef, sex)
+        if(is.infinite(new_loglik)) {
+            break
         }
-    return(proba)
     }
+    return(list(proba = proba, theta = param$theta, loglik = new_loglik, BIC = compute_bic(x, new_loglik, sex)))
+}
+```
 
+# clustering XY
 
-proba <- data %>%
+```{r}
+model_XY <- data %>%
     dplyr::select(count_m, count_f) %>%
     as.matrix() %>% 
     EM_clust()
 data %>%
     dplyr::select(count_m, count_f) %>%
     as.matrix() %>% 
-    plot_proba(proba)
+    plot_proba(model_XY$proba)
+```
+    
+# clustering XO
 
-proba <- data %>%
+```{r}
+model_XO <- data %>%
     dplyr::select(count_m, count_f) %>%
     as.matrix() %>% 
     EM_clust(sex = "X0")
 data %>%
     dplyr::select(count_m, count_f) %>%
     as.matrix() %>% 
-    plot_proba(proba, sex = "X0")
+    plot_proba(model_XO$proba, sex = "X0")
 ```
 
+# LRT
+
+## For XY
 
 ```{r}
-theta4 <- list(
-    "pi" = c(.1, .05, .85),
-    "mu" = list(c(1000, 2000, 1000, 2000), c(1000, 0, 1000, 0), c(1000, 1000, 1000, 1000)),
-    "sigma" = list(
-        "f" = diag(1000, nrow=4, ncol=4),
-        "m" = diag(1000, nrow=4, ncol=4),
-        "a" = diag(1000, nrow=4, ncol=4)
-    )
-)
-proba4 <- data %>%
+data <- sim_kmer(1e3, 1000, "XY")
+model_XY <- data %>%
+    dplyr::select(count_m, count_f) %>%
+    as.matrix() %>% 
+    EM_clust()
+model_XO <- data %>%
     dplyr::select(count_m, count_f) %>%
-    dplyr::mutate(
-        count_m2 = count_m,
-        count_f2 = count_f) %>%
     as.matrix() %>% 
-    EM_clust(theta4)
+    EM_clust(sex = "XO")
+model_XY$BIC
+model_XO$BIC
+-2 * (model_XY$loglik - model_XO$loglik)
+-2 * (model_XO$loglik - model_XY$loglik)
+pchisq(-2 * (model_XY$loglik - model_XO$loglik), 4)
+pchisq(-2 * (model_XO$loglik - model_XY$loglik), 4)
+```
 
-data %>%
+## For XO
+
+```{r}
+data <- sim_kmer(1e3, 1000, "XO")
+model_XY <- data %>%
+    dplyr::select(count_m, count_f) %>%
+    as.matrix() %>% 
+    EM_clust()
+model_XO <- data %>%
     dplyr::select(count_m, count_f) %>%
     as.matrix() %>% 
-    plot_proba(proba4)
+    EM_clust(sex = "XO")
+model_XY$BIC
+model_XO$BIC
+- 2 * (model_XY$loglik - model_XO$loglik)
+- 2 * (model_XO$loglik - model_XY$loglik)
+pchisq(-2 * (model_XY$loglik - model_XO$loglik), 4)
+pchisq(-2 * (model_XO$loglik - model_XY$loglik), 4)
 ```
 
 ## With real data