Author Archives: Robins

[Solved] cv2.error: OpenCV(4.5.1) XXX\shapedescr.cpp:315: error: (-215:Assertion failed) npoints ＞= 0 &&……

Error resolution

Error reproduction

Traceback (most recent call last):
  File "D:/pythonProjects/Object_movement/object_movement.py", line 88, in <module>
    c = max(cnts, key=cv2.contourArea)
cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-i1s8y2i1\opencv\modules\imgproc\src\shapedescr.cpp:315: error: (-215:Assertion failed) npoints >= 0 && (depth == CV_32F || depth == CV_32S) in function 'cv::contourArea'

source code

cnts = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
                            cv2.CHAIN_APPROX_SIMPLE)
cnts=cnts[1]

Modified code

cnts, hierarchy = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
                                       cv2.CHAIN_APPROX_SIMPLE)

Error reporting reason

New CV2 Findcontours returns two values. The result of [0] is contour instead of [1]

[Solved] Job for docker.service failed because the control process exited with error

Error Messages:
Job for docker.service failed because the control process exited with error code. See “systemctl status docker.service” and “journalctl -xe” for details.

Solution:

sudo yum update

After the update, you can start.

ERROR: cannot launch node of type [amcl/amcl]: amcl

ERROR: cannot launch node of type [amcl/amcl]: amcl
ROS path [0]=/opt/ros/kinetic/share/ros
ROS path [1]=/home/robot/catkin_ws/src
ROS path [2]=/opt/ros/kinetic/share
ERROR: cannot launch node of type [move_base/move_base]: move_base
ROS path [0]=/opt/ros/kinetic/share/ros
ROS path [1]=/home/robot/catkin_ws/src
ROS path [2]=/opt/ros/kinetic/share

Solution:

sudo apt-get install ros-kinetic-navigation

[Solved] CentOS Use Yum to install dependency: error: rpmdb open failed

When installing dependencies using Yum in CentOS, the following errors are reported:

the solution is as follows:

Execute the following commands in order

 # Go to the directory where rpmdb is located
 cd /var/lib/rpm
 # Clear the original rpmdb file
 rm -f __db.*
 # Rebuild the rpm database
 rpm --rebuilddb
 # Clear all yum caches
 yum clean all

After execution, use Yum to install the dependent packages normally

[Solved] Nginx cannot access pictures on FTP Error: Whitelabel error page

1. Unable to access the picture

As can be seen from the above figure, whether the full path home/ftpuser/image access or/image access is used, the image access fails.

Let’s solve this problem

2. Configure nginx image access path

# Go to the conf directory of nginx, and find nginx.conf

# Edit profile
vi nginx.conf

# nginx.conf Add Configuration
location /image {
	alias /home/ftpuser/image;
	autoindex on;
}

3. Restart nginx

./nginx -s reload

4. Picture access succeeded

BlazingSQL Error: AttributeError: module ‘cio‘ has no attribute ‘RunQueryError‘

When using blazingsql, the following error was encountered:

Exception:
java.lang.IllegalStateException: Unable to instantiate java compiler
at org.apache.calcite.rel.metadata.JaninoRelMetadataProvider.compile(JaninoRelMetadataProvider.java:433)
at org.apache.calcite.rel.metadata.JaninoRelMetadataProvider.load3(JaninoRelMetadataProvider.java:374)
at org.apache.calcite.rel.metadata.JaninoRelMetadataProvider.lambda$static$0(JaninoRelMetadataProvider.java:109)
at com.google.common.cache.CacheLoader$FunctionToCacheLoader.load(CacheLoader.java:151)
·····

File "/root/bsqlserver/gce_app/libs/bsql_util.py", line 22, in jsonstr_bsql_exec
gdf = bc.sql(sql)
File "/usr/local/envs/bsql/lib/python3.7/site-packages/pyblazing/apiv2/context.py", line 2880, in sql
except cio.RunQueryError as e:
AttributeError: module 'cio' has no attribute 'RunQueryError'

Possible causes: blazingsql modules are imported in multiple places
keep a from blazingsql import blazingcontext to restore normal operation

[Solved] Win10 install Ubuntu error: wslregisterdistribution failed with error: 0x8007019e

This article is reproduced in \ Author: Buyan \ original text: win10 installs Ubuntu system and reports the error wslregisterdistribution failed with error: 0x8007019e – jova – blog Garden (cnblogs. Com)

When installing the Ubuntu system in the windows app store, the error wslregisterdistribution failed with error: 0x8007019e is reported

1. Error reporting:

Installing, this may take a few minutes... Installation Failed! Error: 0x8007019e Press any key to continue...

2. Cause: Windows subsystem support is not installed.

3. Solution:

1. Win + X, select windows PowerShell (administrator)

2. Input: enable windowsoptionalfeature – Online – featurename Microsoft Windows subsystem Linux

3. Enter, enter y, restart!

4. Reopen the installed subsystem, wait a few minutes, and enter the account and password.

error C4996: ‘pcl::SAC_SAMPLE_SIZE‘ [How to Solve]

Error: pcl-1.8\pcl\sample_consensus\model_types.h(99): error C4996: ‘pcl::SAC_SAMPLE_SIZE’: This map is deprecated and is kept only to prevent breaking existing user code. Starting from PCL 1.8.0 model sample size is a protected member of the SampleConsensusModel class

Solution:
Open the project property page > C/C++ > General > SDL Check (set to No).

[Solved] MAC Compile Error: fatal error: ‘endian.h‘ file not found

Specific error

In file included from conf.c:427:
In file included from ../include/local.h:146:
In file included from ../include/sound/asound.h:4:
../include/alsa/sound/uapi/asound.h:31:10: fatal error: 'endian.h' file not
      found
#include <endian.h>

Solution:

Change to <machine/endian.h> Just.

Others say it should be changed to <Endian.h>, Tried, it didn’t work!