diff --git a/bin/plot_positioner b/bin/plot_positioner
index 0a5d0922..13860933 100755
--- a/bin/plot_positioner
+++ b/bin/plot_positioner
@@ -7,53 +7,7 @@ import matplotlib.pyplot as plt
 import numpy as np
 from astropy.table import Table
 from pkg_resources import resource_filename
-
-def parse_fibers(fiber_string) :
-    """
-    Short func that parses a string containing a comma separated list of 
-    integers, which can include ":" or ".." or "-" labeled ranges
-
-    Args:
-        fiber_string (str) : list of integers or integer ranges
-
-    Returns (array 1-D):
-        1D numpy array listing all of the integers given in the list,
-        including enumerations of ranges given.
-
-    Note: this follows python-style ranges, i,e, 1:5 or 1..5 returns 1, 2, 3, 4
-    """
-    if fiber_string is None :
-        return np.array([])
-    else:
-        fiber_string = str(fiber_string)
-
-    if len(fiber_string.strip(' \t'))==0:
-        return np.array([])
-
-    fibers=[]
-
-
-    for sub in fiber_string.split(',') :
-        sub = sub.replace(' ','')
-        if sub.isdigit() :
-            fibers.append(int(sub))
-            continue
-
-        match = False
-        for symbol in [':','..','-']:
-            if not match and symbol in sub:
-                tmp = sub.split(symbol)
-                if (len(tmp) == 2) and tmp[0].isdigit() and tmp[1].isdigit() :
-                    match = True
-                    for f in range(int(tmp[0]),int(tmp[1])) :
-                        fibers.append(f)
-
-        if not match:
-            print("parsing error. Didn't understand {}".format(sub))
-            sys.exit(1)
-
-    return np.array(fibers)
-
+from desimeter.util import parse_fibers
 
 parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter,
                                      description="""Plot FVC spots, showing residuals with metrology""")
diff --git a/py/desimeter/util.py b/py/desimeter/util.py
new file mode 100644
index 00000000..5cd3ebb0
--- /dev/null
+++ b/py/desimeter/util.py
@@ -0,0 +1,51 @@
+"""
+Utility functions
+"""
+
+import numpy as np
+
+def parse_fibers(fiber_string) :
+    """
+    Short func that parses a string containing a comma separated list of 
+    integers, which can include ":" or ".." or "-" labeled ranges
+
+    Args:
+        fiber_string (str) : list of integers or integer ranges
+
+    Returns (array 1-D):
+        1D numpy array listing all of the integers given in the list,
+        including enumerations of ranges given.
+
+    Note: this follows python-style ranges, i,e, 1:5 or 1..5 returns 1, 2, 3, 4
+    """
+    if fiber_string is None :
+        return np.array([])
+    else:
+        fiber_string = str(fiber_string)
+
+    if len(fiber_string.strip(' \t'))==0:
+        return np.array([])
+
+    fibers=[]
+
+
+    for sub in fiber_string.split(',') :
+        sub = sub.replace(' ','')
+        if sub.isdigit() :
+            fibers.append(int(sub))
+            continue
+
+        match = False
+        for symbol in [':','..','-']:
+            if not match and symbol in sub:
+                tmp = sub.split(symbol)
+                if (len(tmp) == 2) and tmp[0].isdigit() and tmp[1].isdigit() :
+                    match = True
+                    for f in range(int(tmp[0]),int(tmp[1])) :
+                        fibers.append(f)
+
+        if not match:
+            print("parsing error. Didn't understand {}".format(sub))
+            sys.exit(1)
+
+    return np.array(fibers)