Remove converting scalar input to numpy data type

Author: junchaoxia

src/aspire/source/__init__.py

@@ -416,10 +416,10 @@ def invert_contrast(self, batch_size=512):
 
         if signal_mean < noise_mean:
             logger.info('Need to invert contrast')
-            scale_factor = np.array(-1.0)
+            scale_factor = -1.0
         else:
             logger.info('No need to invert contrast')
-            scale_factor = np.array(1.0)
+            scale_factor = 1.0
 
         logger.info('Adding Scaling Xform to end of generation pipeline')
         self.generation_pipeline.add_xform(Multiply(scale_factor))

src/aspire/source/xform.py

@@ -130,7 +130,7 @@ def __init__(self, factor):
         :param factor: An ndarray of scalar factors to use for amplitude multiplication.
         """
         super().__init__()
-        self.multipliers = factor
+        self.multipliers = np.array(factor)
 
     def _forward(self, im, indices):
         if self.multipliers.size == 1:
@@ -165,7 +165,7 @@ def __init__(self, shifts):
         :param shifts: An ndarray of shape (n, 2)
         """
         super().__init__()
-        self.shifts = shifts
+        self.shifts = np.array(shifts)
         self.n = shifts.shape[0]
 
     def _forward(self, im, indices):
@@ -257,7 +257,7 @@ def __init__(self, addend):
         :param addend: An ndarray of shape (n,)
         """
         super().__init__()
-        self.addend = addend
+        self.addend = np.array(addend)
 
     def _forward(self, im, indices):
         if self.addend.size == 1: