Update msynth.py

msynth.py

@@ -140,7 +140,7 @@ class msynth(datasets.GeneratorBasedBuilder):
                     "mhd": datasets.Value("string"),
                     "loc": datasets.Value("string"),                 
                     "density": datasets.Value("string"),
-                    "mass_radius": datasets.Value("float32")
+                    "mass_radius": datasets.Value("string")
                 }
             )