Modify the main docstring.

This is meant to correct the impression that this base class is predominantly meant for fitting.

Author: rayosborn

base_classes/NXparameters.nxdl.xml

@@ -29,34 +29,36 @@
     <doc>
         Container for parameters used in processing or analysing data.
 
-        This base class can be used in a number of different contexts,
-        and is allowed in any other base class. However, a common use
-        case is to store the results of optimizing parameters, for
-        example, by least-squares fitting, so a number of attributes
-        have been defined for this purpose. Normally, this group will be
-        stored in a :ref:`NXprocess group`, which defines the program
-        used to process these parameters. If multiple functions are used
-        to analyze the data, there can be additional NXparameter groups
-        for each one.        
+        Typically, this group is stored in a :ref:`NXprocess` group in
+        order to contain parameters that are either inputs to or
+        resulting from the process defined by the parent group. However,
+        this base class can also be added to other groups for use in
+        other contexts.
+        
+        The base class defines a number of attributes that can be used
+        if the parameter values result from, e.g., fitting a function or
+        model to the measured data. If multiple functions are used,
+        there can be additional NXparameter groups for each one.        
     </doc>
     <attribute name="model">
         <doc>
-            The name of the model used in optimizing the data. Fitting
-            packages such as LMFIT (https://lmfit.github.io/lmfit-py/)
-            provide models, which instantiate functions to be fitted to
-            the data. If this attribute is provided, it is assumed that
-            all the parameters in this group are associated with this
-            model.
+            The name of the model used in optimizing the parameter
+            values. Fitting packages such as LMFIT
+            (https://lmfit.github.io/lmfit-py/) provide models, which
+            instantiate functions to be fitted to the data. If this
+            attribute is provided, it is assumed that all the parameters
+            in this group are associated with this model.
         </doc>
     </attribute>
-    <field name="TERM" type="NX_CHAR_OR_NUMBER" nameType="any">
+    <field name="PARAMETER" type="NX_CHAR_OR_NUMBER" nameType="any">
         <doc>
             A parameter that is used in or results from processing. 
         </doc>
         <attribute name="units" />
         <attribute name="error" type="NX_NUMBER">
             <doc>
-                The standard deviation resulting from data optimization.
+                The standard deviation of the parameter after optimizing
+                its value.
             </doc>
         </attribute>
         <attribute name="expression">
@@ -70,23 +72,22 @@
         </attribute>
         <attribute name="initial_value" type="NX_NUMBER">
             <doc>
-                The initial value of the parameter.
+                The initial value of the parameter used in optimization.
             </doc>
         </attribute>
         <attribute name="max" type="NX_NUMBER">
             <doc>
-                The upper bound of the parameter value.
+                The upper bound of the parameter used in optimization.
             </doc>
         </attribute>
         <attribute name="min" type="NX_NUMBER">
             <doc>
-                The lower bound of the parameter value.
+                The lower bound of the parameter used in optimization.
             </doc>
         </attribute>
         <attribute name="vary" type="NX_BOOLEAN">
             <doc>
-                True if the parameter was varied in the fitting
-                procedure.
+                True if the parameter was varied during optimization.
             </doc>
         </attribute>
     </field>