fixing a slly error in SIfloat.

pykat/SIfloat.py

@@ -9,24 +9,24 @@ def SIfloat(value):
         return convertToFloat(value)
     
 def convertToFloat(value):
-    __prefix = {'y': 1e-24,  # yocto
-                'z': 1e-21,  # zepto
-                'a': 1e-18,  # atto
-                'f': 1e-15,  # femto
-                'p': 1e-12,  # pico
-                'n': 1e-9,   # nano
-                'u': 1e-6,   # micro
-                'm': 1e-3,   # mili
-                'c': 1e-2,   # centi
-                'd': 1e-1,   # deci
-                'k': 1e3,    # kilo
-                'M': 1e6,    # mega
-                'G': 1e9,    # giga
-                'T': 1e12,   # tera
-                'P': 1e15,   # peta
-                'E': 1e18,   # exa
-                'Z': 1e21,   # zetta
-                'Y': 1e24,   # yotta
+    __prefix = {'y': 'e-24',  # yocto
+                'z': 'e-21',  # zepto
+                'a': 'e-18',  # atto
+                'f': 'e-15',  # femto
+                'p': 'e-12',  # pico
+                'n': 'e-9',   # nano
+                'u': 'e-6',   # micro
+                'm': 'e-3',   # mili
+                'c': 'e-2',   # centi
+                'd': 'e-1',   # deci
+                'k': 'e3',    # kilo
+                'M': 'e6',    # mega
+                'G': 'e9',    # giga
+                'T': 'e12',   # tera
+                'P': 'e15',   # peta
+                'E': 'e18',   # exa
+                'Z': 'e21',   # zetta
+                'Y': 'e24',   # yotta
                 }
     value = str(value)
     for i, j in __prefix.iteritems():