feat: добавлен Корреляционный анализ (#54)

Closes #31

statapp/models/correlation_analysis_model.py

@@ -0,0 +1,23 @@
+from PySide2.QtCore import QModelIndex, Qt
+
+from statapp.models.ro_table_model import ROTableModel
+from statapp.models.utils import yx_header
+
+
+class CorrelationAnalysisModel(ROTableModel):
+    def __init__(self, data):
+        super().__init__(data)
+
+    def getHorizontalHeader(self):
+        return yx_header(self.columnCount(QModelIndex()))
+
+    def getVerticalHeader(self):
+        return yx_header(self.rowCount(QModelIndex()))
+
+    def data(self, index, role):
+        if role == Qt.DisplayRole:
+            if (index.column() <= index.row()):
+                return float(self._data[index.row(), index.column()])
+            else:
+                None
+        return None