From aebc66dcaaad73a0c6948f81ab06697f3db632e4 Mon Sep 17 00:00:00 2001
From: KIU Shueng Chuan <nixchuan@gmail.com>
Date: Sun, 1 Aug 2021 10:45:29 +0800
Subject: [PATCH] fix log mode by reverting to previous formulation

this formulation is in the documentation for setLogMode()
---
 pyqtgraph/graphicsItems/PlotDataItem.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyqtgraph/graphicsItems/PlotDataItem.py b/pyqtgraph/graphicsItems/PlotDataItem.py
index 97c8cb55..0c6b68a8 100644
--- a/pyqtgraph/graphicsItems/PlotDataItem.py
+++ b/pyqtgraph/graphicsItems/PlotDataItem.py
@@ -701,7 +701,7 @@ class PlotDataItem(GraphicsObject):
                     eps = np.finfo(y.dtype).eps
                 else:
                     eps = 1
-                y = np.copysign(np.log10(np.abs(y)+eps), y)
+                y = np.sign(y) * np.log10(np.abs(y)+eps)
 
         ds = self.opts['downsample']
         if not isinstance(ds, int):