[c++/m] Refactor nix.Tag retrieveData function

- renamed existing function to retrieveDataIdx to stay consistent
  with existing index functions.
- removed index manipulation on matlab side to stay consistent
  with existing index functions.
- rewrote existing test.

Author: mpsonntag

+nix/Tag.m

@@ -63,10 +63,8 @@
                 'Tag::openReferenceIdx', idx, @nix.DataArray);
         end;
 
-        function data = retrieve_data(obj, index)
-            % convert Matlab-like to C-like index
-            assert(index > 0, 'Subscript indices must be positive');
-            tmp = nix_mx('Tag::retrieveData', obj.nix_handle, index - 1);
+        function data = retrieve_data_idx(obj, idx)
+            tmp = nix_mx('Tag::retrieveDataIdx', obj.nix_handle, idx);
 
             % data must agree with file & dimensions
             % see mkarray.cc(42)

nix_mx.cc

@@ -317,7 +317,6 @@ void mexFunction(int            nlhs,
             .reg("sourceCount", GETTER(nix::ndsize_t, nix::Tag, sourceCount))
             .reg("referenceCount", GETTER(nix::ndsize_t, nix::Tag, referenceCount))
             .reg("featureCount", GETTER(nix::ndsize_t, nix::Tag, featureCount));
-        methods->add("Tag::retrieveData", nixtag::retrieveData);
         methods->add("Tag::featureRetrieveData", nixtag::retrieveFeatureData);
         methods->add("Tag::addReference", nixtag::addReference);
         methods->add("Tag::addReferences", nixtag::addReferences);
@@ -331,6 +330,7 @@ void mexFunction(int            nlhs,
         methods->add("Tag::sourcesFiltered", nixtag::sourcesFiltered);
         methods->add("Tag::referencesFiltered", nixtag::referencesFiltered);
         methods->add("Tag::featuresFiltered", nixtag::featuresFiltered);
+        methods->add("Tag::retrieveDataIdx", nixtag::retrieveDataIdx);
 
         classdef<nix::MultiTag>("MultiTag", methods)
             .desc(&nixmultitag::describe)

src/nixtag.cc

@@ -63,14 +63,6 @@ namespace nixtag {
         output.set(0, handle(newFeat));
     }
 
-    void retrieveData(const extractor &input, infusor &output) {
-        nix::Tag currObj = input.entity<nix::Tag>(1);
-        double index = input.num<double>(2);
-
-        mxArray *data = make_mx_array_from_ds(currObj.retrieveData(index));
-        output.set(0, data);
-    }
-
     void retrieveFeatureData(const extractor &input, infusor &output) {
         nix::Tag currObj = input.entity<nix::Tag>(1);
         double index = input.num<double>(2);
@@ -130,4 +122,12 @@ namespace nixtag {
         output.set(0, res);
     }
 
+    void retrieveDataIdx(const extractor &input, infusor &output) {
+        nix::Tag currObj = input.entity<nix::Tag>(1);
+        nix::ndsize_t idx = (nix::ndsize_t)input.num<double>(2);
+
+        mxArray *data = make_mx_array_from_ds(currObj.retrieveData(idx));
+        output.set(0, data);
+    }
+
 } // namespace nixtag

src/nixtag.h

@@ -25,8 +25,6 @@ namespace nixtag {
 
     void createFeature(const extractor &input, infusor &output);
 
-    void retrieveData(const extractor &input, infusor &output);
-
     void retrieveFeatureData(const extractor &input, infusor &output);
 
     void openReferenceIdx(const extractor &input, infusor &output);
@@ -43,6 +41,8 @@ namespace nixtag {
 
     void featuresFiltered(const extractor &input, infusor &output);
 
+    void retrieveDataIdx(const extractor &input, infusor &output);
+
 } // namespace nixtag
 
 #endif

tests/TestTag.m

@@ -34,7 +34,7 @@
     funcs{end+1} = @test_open_reference_idx;
     funcs{end+1} = @test_set_metadata;
     funcs{end+1} = @test_open_metadata;
-    funcs{end+1} = @test_retrieve_data;
+    funcs{end+1} = @test_retrieve_data_idx;
     funcs{end+1} = @test_retrieve_feature_data;
     funcs{end+1} = @test_attrs;
     funcs{end+1} = @test_has_feature;
@@ -524,14 +524,28 @@
     assert(strcmp(t.open_metadata.name, 'testSection'));
 end
 
-%% Test: Retrieve data
-function [] = test_retrieve_data( varargin )
-    f = nix.File(fullfile(pwd, 'tests', 'test.h5'), nix.FileMode.ReadOnly);
-    b = f.blocks{1};
-    tag = b.open_tag('Arm movement epoch Trial 001');
-    
-    data = tag.retrieve_data(1);
-    assert(~isempty(data));
+%% Test: Retrieve referenced data by index
+function [] = test_retrieve_data_idx( varargin )
+    f = nix.File(fullfile(pwd, 'tests', 'testRW.h5'), nix.FileMode.Overwrite);
+    b = f.create_block('testBlock', 'nixBlock');
+    raw = [1, 2, 3, 4, 5, 6, 7, 8, 9];
+    d = b.create_data_array_from_data('testDataArray', 'nixDataArray', raw);
+    d.append_sampled_dimension(1);
+    % tag positon is used like an index, therfore starts with 0!
+    tagStartPos = [3];
+    t = b.create_tag('testTag', 'nixTag', tagStartPos);
+    t.extent = [3];
+    t.add_reference(d);
+
+    try
+        t.retrieve_data_idx(12);
+    catch ME
+        assert(~isempty(strfind(ME.message, 'out of bounds')), 'Invalid index failed');
+    end
+
+    retData = t.retrieve_data_idx(0);
+    assert(size(retData, 2) == t.extent, 'Extent check failed');
+    assert(retData(1) == raw(t.position + 1), 'Position check failed');
 end
 
 %% Test: Retrieve feature data