lm __init__.py Added check for healpy version

lm/__init__.py

@@ -21,12 +21,17 @@
 
 from __future__ import division
 from nifty import about
+
+from distutils.version import LooseVersion as lv
+
 #from nifty_lm import *
 try:
     import libsharp_wrapper_gl as gl
 except(ImportError):
     try:
         import healpy as hp
+        if lv(hp.__version__) <= lv('1.8.1'):
+            raise ImportError(about._errors.cprint("ERROR: installed healpy version is older than 1.8.1!"))
     except(ImportError):
         about.infos.cprint("INFO: neither libsharp_wrapper_gl nor healpy available.")
         pass ## import nothing
@@ -36,9 +41,11 @@ except(ImportError):
 else:
     try:
         import healpy as hp
+        if lv(hp.__version__) <= lv('1.8.1'):
+            raise ImportError(about._errors.cprint("ERROR: installed healpy version is older than 1.8.1!"))
     except(ImportError):
         from nifty_lm import lm_space,gl_space ## import lm & gl
-    else:
+    else:        
         from nifty_lm import lm_space,gl_space,hp_space ## import all 3
 from nifty_power_conversion_lm import *