fixed fabs issue

9 jobs for common-laplacians in 4 minutes and 6 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #106568
VS2015
VS2015-32-bit

00:01:24

passed #106567
VS2015
VS2015-64-bit

00:01:31

passed #106566
VS2017
VS2017-32-bit

00:01:11

passed #106565
VS2015
VS2017-64-bit

00:01:37

passed #106562
Linux
clang-c++11

00:03:01

passed #106564
Linux
cppcheck

00:03:34

passed #106569
Linux
doc

00:00:04

passed #106561
Linux
gcc-c++11

00:02:39

passed #106563
Apple
macos-c++11

00:01:48