--- a
+++ b/R/FourDegsVenn.R
@@ -0,0 +1,51 @@
+#' Function to Filter Differentially Expressed Genes (DEGs)
+#'
+#' This function filters out genes based on their expression change status.
+#' It returns the names of genes which are not "stable".
+#'
+#' @param df A data frame containing gene expression data.
+#' @return A vector of gene names that are differentially expressed.
+#' @examples
+#' DEG_deseq2_file <- system.file("extdata", "DEG_deseq2.rds", package = "TransProR")
+#' DEG_deseq2 <- readRDS(DEG_deseq2_file)
+#' DEG_deseq2_test <- deg_filter(DEG_deseq2)
+#' @export
+
+deg_filter <- function(df){
+  # Selecting gene names where change is not "stable"
+  rownames(df)[df$change != "stable"]
+}
+
+#' Function to Create a Venn Diagram of DEGs
+#'
+#' This function creates a Venn Diagram using the ggVennDiagram package.
+#' It allows customization of various aesthetic elements of the diagram.
+#' @importFrom ggplot2 alpha scale_fill_gradient scale_color_manual scale_x_continuous expansion
+#' @importFrom ggVennDiagram ggVennDiagram
+#' @param degs_list A list of DEG sets for Venn Diagram creation.
+#' @return A ggplot object representing the Venn Diagram.
+#' @examples
+#' data("all_degs_venn", package = "TransProR")
+#' four_degs_venn <- four_degs_venn(all_degs_venn)
+#' @export
+
+four_degs_venn <- function(degs_list){
+  # Defining edge colors and alpha transparency for the Venn Diagram
+  edge_colors <- c(ggplot2::alpha("#1b64bb", 0.5), ggplot2::alpha("#13828e", 0.5),
+                   ggplot2::alpha("#337c3a", 0.5), ggplot2::alpha("#9e9d39", 0.5))
+  edge_color <- ggplot2::alpha(c("#1b64bb","#13828e","#337c3a","#9e9d39"), 0.8)
+
+  # Creating a Venn Diagram using 'ggVennDiagram'
+  ggVennDiagram::ggVennDiagram(
+    degs_list,
+    set_size = 5,  # Font size for group names
+    set_color = edge_color,  # Color for group names
+    label_alpha= 0,  # Transparency of background box for labels
+    label_size = 4,  # Font size for labels
+    edge_size = 3   # Thickness of edges
+  ) +
+    ggplot2::scale_fill_gradient(low="#e1f2f1", high = "#11786b") +  # Gradient fill based on values
+    ggplot2::scale_color_manual(values = edge_colors) +  # Manually set edge colors
+    ggplot2::scale_x_continuous(expand = ggplot2::expansion(mult = .3))  # Adjusting x-axis scaling
+}
+