diff --git a/Controller/common_functions.py b/Controller/common_functions.py
new file mode 100644
index 0000000000000000000000000000000000000000..2473b5702edda9d890f93678fb8e2909a0745fcd
--- /dev/null
+++ b/Controller/common_functions.py
@@ -0,0 +1,90 @@
+import numpy as np
+import scipy.stats as sp
+# from decimal import Decimal
+from sigfig import round as sigfig_round
+
+def units_conversion(units_id="SI"):
+    """Computes the units conversion from SI units used internally to the
+    desired display units.
+
+    Parameters
+    ----------
+    units_id: str
+        String variable identifying units (English, SI) SI is the default.
+
+    Returns
+    -------
+    units: dict
+        dictionary of unit conversion and labels
+    """
+
+    if units_id == "SI":
+        units = {
+            "L": 1,
+            "Q": 1,
+            "A": 1,
+            "V": 1,
+            "label_L": "m",
+            "label_Q": "m3/s",
+            "label_A": "m2",
+            "label_V": "m/s",
+            "ID": "SI",
+        }
+
+    else:
+        units = {
+            "L": 1.0 / 0.3048,
+            "Q": (1.0 / 0.3048) ** 3,
+            "A": (1.0 / 0.3048) ** 2,
+            "V": 1.0 / 0.3048,
+            "label_L": "ft",
+            "label_Q": "ft3/s",
+            "label_A": "ft2",
+            "label_V": "ft/s",
+            "ID": "English",
+        }
+
+    return units
+
+
+def convert_temperature(temp_in, units_in, units_out) -> float:
+    """Converts temperature from F to C or C to F.
+
+    Parameters
+    ==========
+    temp_in: np.array
+        temperature in units_in
+    units_in: str
+        C for Celcius or F for Fahrenheit
+    units_out: str
+        C for Celcius or F for Fahrenheit
+
+    Returns
+    =======
+    temp_out: np.array
+        temperature in units_out
+    """
+
+    temp_out = None
+    if units_in == "F":
+        if units_out == "C":
+            temp_out = (temp_in - 32) * (5.0 / 9.0)
+        else:
+            temp_out = temp_in
+
+    elif units_in == "C":
+        if units_out == "C":
+            temp_out = temp_in
+        else:
+            temp_out = (temp_in * (9.0 / 5.0)) + 32
+
+    return temp_out
+
+
+def scientific_notation(n, sig: int = 3):
+    if np.isnan(n):
+        n = 0
+    elif np.isinf(n):
+        return n
+
+    return sigfig_round(n, sig)
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