1 files changed, 6 insertions, 0 deletions
diff --git a/R/HS.R b/R/HS.R
new file mode 100644
index 0000000..0755c90
--- /dev/null
+++ b/R/HS.R
@@ -0,0 +1,6 @@
+HS <- function(t, parent.0, k1, k2, tb)
+{
+	parent = ifelse(t <= tb, 
+		parent.0 * exp(-k1 * t),
+		parent.0 * exp(-k1 * tb) * exp(-k2 * (t - tb)))
+}