add conversion of a float typed variable

source/tensor/core/getandset/SetData.cpp

@@ -70,7 +70,7 @@ void _SetDataFanInOut(XTensor * tensor, DTYPE gain)
         fanOut = numOutputFmaps * receptiveFieldSize;
     }
 
-    DTYPE std = gain * sqrt(2.0/(fanIn + fanOut));
+    DTYPE std = gain * (float)sqrt(2.0/(fanIn + fanOut));
     DTYPE a = sqrt(3.0) * std;
     _SetDataRand(tensor, -a, a);
 }