Introduce plot to file function

sma_plot_file(fname, ftype, title_list, legend_list, fun, ...)
can be used to write plot to a file.
It supports all output filetypes R can handle. Title and legend
arguments can be passed as lists.
All available plotting functions can be used, arguments go into a
variable argument list.

utils.R

@@ -0,0 +1,28 @@
+# secMalASCT utilities
+#
+# License: GPL version 3
+# Jens Mathis Sauer (c) 2020
+
+#
+# Write plot to filename
+#
+# This will plot "fun" with arguments "..." as filetype "ftype" and
+# the output to "filename". Title and legends can be passed as list,
+# or NULL if not needed.
+# Default filesize is 3000x3000 px and 300 dpi resolution.
+#
+sma_plot_file <- function(fname, ftype, title_list, legend_list, fun, ...) {
+	# Open file for writing
+	ftype(filename = fname, width = 3000, height = 3000, res = 300)
+
+	# run "fun" with passed arguments
+	do.call(fun, list(...))
+
+	if (!is.null(title_list)) {
+		do.call(title, title_list)
+	}
+	if(!is.null(legend_list)) {
+		do.call(legend, legend_list)
+	}
+	dev.off()
+}