From a2fb00633aa1ae64952eb61e97df2763fdbb966b Mon Sep 17 00:00:00 2001
From: Kenneth Lyons <ixjlyons@gmail.com>
Date: Fri, 7 Jun 2019 00:00:30 -0700
Subject: [PATCH] DeMorgans the logic for better readability.

---
 pyqtgraph/graphicsItems/ErrorBarItem.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pyqtgraph/graphicsItems/ErrorBarItem.py b/pyqtgraph/graphicsItems/ErrorBarItem.py
index 5e399e34..5d57e3db 100644
--- a/pyqtgraph/graphicsItems/ErrorBarItem.py
+++ b/pyqtgraph/graphicsItems/ErrorBarItem.py
@@ -46,10 +46,10 @@ class ErrorBarItem(GraphicsObject):
         This method was added in version 0.9.9. For prior versions, use setOpts.
         """
         self.opts.update(opts)
-        if self.opts['x'] is not None and self.opts['y'] is not None:
-            self.setVisible(True)
-        else:
+        if self.opts['x'] is None or self.opts['y'] is None:
             self.setVisible(False)
+        else:
+            self.setVisible(True)
         self.path = None
         self.update()
         self.prepareGeometryChange()