Implemented Dataset.get_indices() and extended Dataset.get_identifiers() to convert between indices and identifiers and subsets thereof.

Also added tests.

test/system/datasettest.py

@@ -21,6 +21,24 @@ class DatasetTest(unittest.TestCase):
         assert data['samples']['sample_b']==1
         assert 'gene_c' in data['genes'].keys()
         assert data['genes']['gene_c']==2
+
+    def testLookupIndicesOfIdentifiers(self):
+        data = self.testdata
+        # base case
+        self.assertEquals([0, 1, 2], data.get_indices('genes', ['gene_a', 'gene_b', 'gene_c']))
+        # "advanced" lookup
+        self.assertEquals([2, 0], data.get_indices('genes', ['gene_c', 'gene_a']))
+        # other dimension
+        self.assertEquals([0, 1], data.get_indices('samples', ['sample_a', 'sample_b']))
+
+    def testLookupIdentifiersOfIndices(self):
+        data = self.testdata
+        # base case
+        self.assertEquals(['gene_a', 'gene_b', 'gene_c'], data.get_identifiers('genes', [0, 1, 2]))
+        # "advanced" lookup
+        self.assertEquals(['gene_c', 'gene_a'], data.get_identifiers('genes', [2, 0]))
+        # other dimension
+        self.assertEquals(['sample_a', 'sample_b'], data.get_identifiers('samples', [0, 1]))
         
     #def testExtraction(self):
     #    ids = ['gene_a','gene_b']