rework fitH5: clean-up, update doc, updat writer API

xsocs/process/fit/peak_fit.py

@@ -157,28 +157,21 @@ class FitResult(object):
 
         with FitH5Writer(fit_h5, mode=mode) as fitH5:
             fitH5.create_entry(fit_name)
+            fitH5.create_process(fit_name, result_name)
 
-            fitH5.set_scan_x(fit_name, self.sample_x)
-            fitH5.set_scan_y(fit_name, self.sample_y)
-
-            q_dim0, q_dim1, q_dim2 = self.qspace_dimension_values
-            fitH5.set_qx(fit_name, q_dim0)
-            fitH5.set_qy(fit_name, q_dim1)
-            fitH5.set_qz(fit_name, q_dim2)
-
+            fitH5.set_sample_positions(fit_name, self.sample_x, self.sample_y)
+            fitH5.set_qspace_dimension_values(
+                fit_name, *self.qspace_dimension_values)
             fitH5.set_background_mode(fit_name, self.background_mode)
-            fitH5.create_process(fit_name, result_name)
 
-            for array, func, axis in zip(
-                    self._fit_results,
-                    (fitH5.set_qx_result, fitH5.set_qy_result, fitH5.set_qz_result),
-                    (0, 1, 2)):
+            for dimension, array in enumerate(self._fit_results):
                 for name in self.available_result_names:
-                    results = self.get_results(axis, name, copy=False)
+                    results = self.get_results(dimension, name, copy=False)
                     if name == 'Status':
-                        fitH5.set_status(fit_name, axis, results)
+                        fitH5.set_status(fit_name, dimension, results)
                     else:
-                        func(fit_name, result_name, name, results)
+                        fitH5.set_result(
+                            fit_name, result_name, dimension, name, results)
 
 
 class PeakFitter(object):