Changed argument of Measurement.exportAsWave() from newsampwidth to dtype, to allow export as float

src/lasp/lasp_measurement.py

@@ -274,7 +274,6 @@ class Measurement:
                 self._qtys = [SIQtys.default() for i in range(self.nchannels)]
                 logging.debug(f'Physical quantity data not available in measurement file. Assuming {SIQtys.default}')
 
-
     def setAttribute(self, atrname, value):
         """
         Set an attribute in the measurement file, and keep a local copy in
@@ -632,8 +631,8 @@ class Measurement:
             return False
 
 
-    def exportAsWave(self, fn=None, force=False, newsampwidth=None,
+    def exportAsWave(self, fn=None, force=False, dtype=None,
-                     normalize=True, **kwargs):
+                     normalize=False, **kwargs):
         """Export measurement file as wave. In case the measurement data is
         stored as floats, the values are scaled to the proper integer (PCM)
         data format.
@@ -645,9 +644,8 @@ class Measurement:
             force: If True, overwrites any existing files with the given name
             , otherwise a RuntimeError is raised.
 
-            newsampwidth: sample width in bytes with which to export the data.
+            dtype: if not None, convert data to this data type.
-            This should only be given in case the measurement data is stored as
+            Options are 'int16', 'int32', 'float32'.
-            floating point values, otherwise an error is thrown
 
             normalize: If set: normalize the level to something sensible.
         """
@@ -661,39 +659,49 @@ class Measurement:
         if os.path.exists(fn) and not force:
             raise RuntimeError(f'File already exists: {fn}')
 
-
         if not np.isclose(self.samplerate%1,0):
             raise RuntimeError(f'Sample rates should be approximately integer for exporting to Wave to work')
 
         # TODO: With VERY large measurment files, this is not possible! Is this
         # a theoretical case?
+        # TODO: add sensitivity? Then use self.data() instead of self.rawData()
         data = self.rawData(**kwargs)
-        if np.issubdtype(data.dtype, np.floating) and newsampwidth is None:
-            raise ValueError('Newsampwidth parameter should be given for floating point raw data')
 
         if normalize:
             # Scale back to maximum of absolute value
             maxabs = np.max(np.abs(data))
             data = data / maxabs  # "data /= maxabs" fails if dtpyes differ
 
-        if newsampwidth is not None:
+        if dtype==None:
-            # Convert to floats, then to new sample width
+            dtype = data.dtype  # keep existing
-            sensone = np.ones_like(self.sensitivity)
+            logging.debug(f"dtype not passed as arg; using dtype = {dtype}")
-            data = scaleBlockSens(data, sensone)
 
-            if newsampwidth == 2:
+        # dtype conversion
-                newtype = np.int16
+        if dtype=='int16':
-            elif newsampwidth == 4:
+            newtype = np.int16
-                newtype = np.int32
+            newsampwidth = 2
-            else:
+        elif dtype=='int32':
-                raise ValueError('Invalid sample width, should be 2 or 4')
+            newtype = np.int32
+            newsampwidth = 4
+        elif dtype=='float32':
+            newtype = np.float32
+        elif dtype=='float64':
+            newtype = np.float64
+        else:
+            logging.debug(f"cannot handle this dtype {dtype}")
+            pass
 
+        # Convert range to [-1, 1]
+        # TODO: this is wrong for float data where full scale > 1
+        sensone = np.ones_like(self.sensitivity)
+        data = scaleBlockSens(data, sensone)
+
+        if dtype=='int16' or dtype=='int32':
+            # Scale data to integer range and convert to integers
             scalefac = 2**(8*newsampwidth-1)-1
-
-            # Scale data to integer range, and then convert to integers
             data = (data*scalefac).astype(newtype)
 
-        wavfile.write(fn, int(self.samplerate), data)
+        wavfile.write(fn, int(self.samplerate), data.astype(newtype))
 
     @staticmethod
     def fromtxt(fn,