diff --git a/iv4.m b/iv4.m
new file mode 100644
index 0000000000000000000000000000000000000000..0d77eeeaaabc6e6902896f26c1e8f4ebd320fd4f
--- /dev/null
+++ b/iv4.m
@@ -0,0 +1,4 @@
+function params = iv4(X, Y, KSZI1)
+    params = (KSZI1'*X)\(KSZI1'*Y);
+end
+