diff --git a/createTestData/doublePointedArrowInside.m b/createTestData/doublePointedArrowInside.m
new file mode 100644
index 0000000000000000000000000000000000000000..c28936fd065371c19e756230ff8e30bb0d6242a2
--- /dev/null
+++ b/createTestData/doublePointedArrowInside.m
@@ -0,0 +1,22 @@
+function doublePointedArrowInside(xa,yUpper,yLower, arrowsColor)
+     set(gcf,'Units','normalized');
+     yaDown = [yUpper+1e-8 yUpper];
+     yaLine = [yLower yUpper];
+     yaUp = [yLower-1e-8 yLower];
+     [xaf,yafLine] = axescoord2figurecoord(xa,yaLine);
+     line = annotation('line',xaf,yafLine);
+     [xaf,yafDown] = axescoord2figurecoord(xa,yaDown);
+     arDown = annotation('arrow',xaf,yafDown);
+     [xaf,yafUp] = axescoord2figurecoord(xa,yaUp);
+     arUp = annotation('arrow',xaf,yafUp);
+     %styling
+     line.Color = arrowsColor;
+     arDown.HeadStyle = 'vback2';
+     arDown.HeadLength = 5;
+     arDown.HeadWidth = 7;
+     arDown.Color = arrowsColor;
+     arUp.HeadStyle = 'vback2';
+     arUp.HeadLength = 5;
+     arUp.HeadWidth = 7;
+     arUp.Color = arrowsColor;
+end
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