diff --git a/src/counts_matrix_generator.R b/src/counts_matrix_generator.R
new file mode 100644
index 0000000000000000000000000000000000000000..4d42d01d009458c55a87304710f58691bfb65122
--- /dev/null
+++ b/src/counts_matrix_generator.R
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+#seed
+library(tidyverse)
+library(data.table)
+
+
+# fix seed
+set.seed(123)
+
+#params
+N_gene = 6000
+
+
+
+## function generator
+rnbinom_generator <- function(n_gene, mu_simul, alpha){
+  
+  my_counts <- rnbinom(n = n_gene, mu = mu_simul, size = alpha)
+  return(my_counts)
+
+  }
+
+
+
+## build my lib counts
+env1 <- rnbinom_generator(N_gene, 50, 5)
+env2 <- rnbinom_generator(N_gene, 100, 5)
+
+
+
+## export my lib count
+names(env1) <- sprintf("gene%d", 1:N_gene)
+names(env2) <- sprintf("gene%d", 1:N_gene)
+env1 %>% data.frame(.) %>% fwrite(., "~/mydatalocal/counts_simulation/env1.csv", row.names = T, col.names = F, sep = "\t")
+env2 %>% data.frame(.) %>% fwrite(., "~/mydatalocal/counts_simulation/env2.csv", row.names = T, col.names = F, sep = "\t")