Torque
$$ {\boldsymbol {\tau }}=\mathbf {r} \times \mathbf {F} $$ $$ \tau =\|\mathbf {r} \|\,\|\mathbf {F} \|\sin \theta $$
#physics
Exploring table partitioning using the inheritance technique.
#postgresql
Moving data to another (archive) table with one query:
WITH moved_rows AS (
DELETE FROM box_magldno.serialno
WHERE tms::DATE <='2018-12-31'
RETURNING *
)
INSERT INTO box_magldno.serialno_2018
SELECT * FROM moved_rows;
#sql #postgresql
Read the temperature and pressure from the BMP280 sensor, using the bmp280 driver and Micropython plugin for Pycharm:
from machine import I2C
from bmp280 import BMP280
bus = I2C(scl=machine.Pin(5), sda=machine.Pin(4))
bmp = BMP280(bus)
bmp.pressure
>>> 97679.8
bmp.temperature
>>> 21.68
#arduino
Blinking the LED on the esp8266
with my son
import machine
pin = machine.Pin(2, machine.Pin.OUT)
pin.off()
pin.on()
#arduino
Regex for adjusting Jupyter notebook exported to markdown to the markdown rendered as HTML with MathJax
In-line math delimiters:
\$\$(.*?)\$\$
\\\\( $1 \\\\)
In-line numbers:
\$\$([\d\.]*?)\$\$
\\\\( $1 \\\\)
Matrices row separator:
\\begin\{bmatrix\}(.*?) \\\\ (.*?)\\end\{bmatrix\}
\\begin\{bmatrix\} $1 \\\\\\ $2 \\end\{bmatrix\}
Images:
!\[png]\((.*?)\)
<center>
<figure class="figure text-center">
<img width="80%" src="/static/art/002/$1" class="figure-img img-fluid rounded">
<figcaption class="figure-caption text-center"></figcaption>
</figure>
Monitoring network traffic
netstat -tp
iftop
tcptrack -i eth0
ss -tn -o
watch -n 1 "ss -tn -o"
Commands to monitor network bandwidth on Linux
#linux
Adding the site to Google Index by requesting the indexing trough the Google Search Console.
#seo
Redirect www
to the non-www
domain for better google search.
How To Redirect www to Non-www with Nginx on CentOS 7
#linux #nginx