June 10, 2017, 10:22 a.m.

Sorting lines in VIM

Sorting lines in VIM works with:


it works perfect for todo.txt file format. http://vim.wikia.com/wiki/Sort_lines https://github.com/ginatrapani/todo.txt-cli/wiki/The-Todo.txt-Format

Jan. 18, 2017, 4:27 p.m.

Using Haroopad for writings


Installing on Fedora: http://www.bonashen.com/post/artifice/20140805-install-haroopad-on-fedora-20-64bit

Jan. 18, 2017, 10:29 a.m.


Designing EDI - Electronic Document(Data) Interchange platform for ERP system.

Jan. 14, 2017, 10:37 a.m.

Jupyter notebook presentation

Creating presentation using amazing extension:


Dec. 10, 2016, 10:19 p.m.

Bitbucket Pipelines

Configuring pytest and bitbucket pipelines. Free CI until the end of 2016

April 24, 2016, 11:10 a.m.

H2 Energy computed with GTO


E = -1.8706052190703892 Ry

R = 1.4186131

March 5, 2016, 3:46 p.m.

Django templating

Transforming paid template into django style blocks.

Sept. 26, 2015, 2:04 p.m.


Density functional theory is a computational quantum mechanical modelling method to investigate the electronic structure (principally the ground state) of many-body systems. Computational costs are relatively low when compared to traditional methods, such as Hartree–Fock theory and its descendants based on the complex many-electron wavefunction.

Aug. 27, 2015, 10:15 a.m.

Computed overlap integral via STOnG

STOnG is basis set for GTO that maps Slater's orbital. Thanks to Gaussian Product Rule GTO are more computationly efficient.

Aug. 17, 2015, 11:10 a.m.

Vim in Chrome & JetBrains

Installed plugins for Vim like navigation - IdeaVim - Vimium

Aug. 17, 2015, 6:20 a.m.

Gaussian Product Rule

The product of two Gaussian functions located on different centers is a new Gaussian function located on a new center. Four-center electron distributions could be reduced to a single-center distributions.

Philip E. HOGGAN "Molecular Integrals over Slater-type Orbitals. From pioneers to recent progress"

June 25, 2015, 6:45 a.m.

STO - Slater-type orbital

Slater type orbital is a mathematic function that describes wave-like behaviour of the electrons in an atom. STOs has no radial nodes. Slater orbitals are the natural basis functions in quantum molecular calculations. Their use has been rather restricted, mostly due to mathematical integration difficulties.

P.E. Hoggan, M.B. Ruiz, and T. Özdogan, Molecular Integrals over Slater-type orbitals. From pioneers to recent progress, in Quantum Frontiers of Atoms and Molecules

June 21, 2015, 9:16 a.m.

The importance of eigenvalues

Eigenvectors make understanding linear transformations easy. They are the "axes" (directions) along which a linear transformation acts simply by "stretching/compressing" and/or "flipping"; eigenvalues give you the factors by which this compression occurs.


May 28, 2015, 10:13 a.m.

B2C product creator

Designing and implementing web B2C creator for photovoltaics sets.

May 28, 2015, 9:10 a.m.

Product bar codes

Creating and implementing solution for labeling every product with unique bar codes, for a demand of automotive industry. Introducing Quality Control procedures basing on the new bar codes.

April 18, 2015, 6:53 p.m.

Checking size of SELECTed data in table


SELECT pg_size_pretty(pg_total_relation_size('tab1'));


March 20, 2015, 7:08 a.m.

Setting Vim as defalut editor


export EDITOR
export VISUAL

and uncheck in mc configuration embedded editor and viewer.

March 11, 2015, 6:12 a.m.

Encrypted file system in file container

The best way to encrypt your private data is to create a file, which can be mount on demand. You can easily move it, copy it, and when mounted use it as a ordinary, mounted file system.


Feb. 28, 2015, 7:06 a.m.

Connect with remote X server

$ ssh -X host

Running any GUI program on remote machine will redirect its its interface to client machine. Be careful it is really slow comparing to rdp or even vnc.

Nov. 24, 2014, 6:51 a.m.

Proffesionall presentations

Creating proffessionall presentation using software:

https://bitbucket.org/rivanvx/beamer http://impressive.sourceforge.net

Nov. 4, 2014, 7:19 a.m.

Notes and sketching on linux

Simple and powerful app for taking hand notes on Linux: "Xournal" combined with : "Nimbus Screen Capture" - editable screenshots provides comfortable way for taking notes from your web researches.

Oct. 28, 2014, 7:48 a.m.

Numerical integration of improper divergent integrals

Computing integrals using Monte Carlo methods and going further with MISER adaptive algorithm. Trying importance sampling. http://http://scikit-monaco.readthedocs.org

July 23, 2014, 12:17 p.m.

Queries optimization with Materialized

Remember complicated queries and caches results. Don't forget about manual refresh after source data changes.


July 10, 2014, 7:01 a.m.

Notes digitization - image optimization

Sharpen and reduce noise on photos from meeting notes.

mogrify -sharpen 0x2 *.jpg
mogrify -type Grayscale *.jpg
mogrify -quality 80 *.jpg

June 24, 2014, 3:59 p.m.

Unit of Work for client's view update

Using Unit of Work pattern in client - server event driven communication. Listing for attribute changes instead of comparing object's copies, looking for differences, at every response.

http://martinfowler.com/eaaCatalog/unitOfWork.html http://docs.doctrine-project.org/en/2.0.x/reference/change-tracking-policies.html http://docs.sqlalchemy.org/en/latest/orm/events.html#sqlalchemy.orm.events.AttributeEvents.set

June 20, 2014, 8:14 a.m.

Customer customization of web app modules

Symfony bundle inheritance


Don't forget about functional testing for every customization.

June 11, 2014, 12:18 p.m.

B2B via XML files

Standard solution for fast defining XML files for various documents in B2B communication.

June 5, 2014, 8:46 a.m.

Keeping up-to-date calculated prices in warehouse

Setting price to zero when old stock is sold. Continuous calculation of actual price for new stock.

June 4, 2014, 12:01 p.m.

Odoo - Opendays June 4-6, 2014


June 4, 2014, 10:04 a.m.

Uwsgi service for CentOS

Creating uwsgi service for CentOS because of Ansible deployment automation.

June 2, 2014, 12:49 p.m.

Application deployment with Ansible

Setting up playbook for automatic upgrade of application on multiple servers.


June 2, 2014, 10 a.m.

Rationalize manufacture registration

Possibilities for recording kanban registration of manufacturing, when material's delivery is still not entered into the erp system.

Tracing costs of services for cooperating departments via the internal orders.

May 15, 2014, 10:33 p.m.

Philosophical implications of QM

The basis of a science is its ability to predict. To predict means to tell what will happen in an experiment that has never been done. Given an arbitrary accuracy, no matter how precise, one can find a time long enough that we cannot make predictions valid for that long a time.

May 15, 2014, 10:24 p.m.

Relativistic Doppler effect

Change in frequency (and wavelength) of light, caused by the relative motion of the source and the observer.

May 2, 2014, 12:24 p.m.

Quantum mechanics - predicting

Quantum mechanics is a predictive theory, not just measurements after the fact. So we must talk about what we can predict, not only what we've already known on the beginning of the experiment.

April 30, 2014, 9:20 a.m.

PostgreSQL loading data performance tips



April 21, 2014, 11:16 a.m.

Backward scheduling

Algorithm for backward scheduling, based on forward scheduling calculation with simple constraints.

April 9, 2014, 12:16 p.m.

Paper digitization

No paper documents. All of them easily accessible through the digital library.

April 8, 2014, 8:11 p.m.

Profiling - sort by cumulative time

cProfile.runctx('foo()'', globals(), locals(), sort=2)

April 1, 2014, 10:19 p.m.

Screen - running task in background

Start virtual terminal

$ screen -S [nameScreen]

Disconnect Ctrl + a Ctrl + d

List all running virtual terminals

$ screen -ls

Connect to terminal

$ screen -r [nameScreen]


April 1, 2014, 8:24 a.m.

Sales complaints

Designing process for sales complaints in trading company. Complaints cases:

Process supported by worklfow. Customer e-mail notification at every stage.

March 25, 2014, 9:57 p.m.

Remove whitespaces from string

sentence = re.sub(re.compile(r'\s+'), '', sentence)

March 20, 2014, 4:48 p.m.

Postgres full-text search

SELECT to_tsvector('If the facts don''t fit the theory, change the facts.') @@ to_tsquery('fiction | theory');


March 18, 2014, 9:25 a.m.

Gvim disable temp and backup files

set nobackup
set noswapfile

March 16, 2014, 9:35 p.m.

Momentum in qunatum mechanics

p =  − iℏ∇

March 12, 2014, 11:04 p.m.

Annihilation in decimal state form

Translating Ket state to binary and then shorten it in decimal form, requires fast method for creation, annihilation for selected node. The value of with the state should by changed can be obtain throughout equation:

22n − 2i + 1 − spin
n − quantityofnodes
i − nodenumber
spin − ↑:0↓:1

March 11, 2014, 8:08 p.m.

How to Read an Academic Article

  1. Read the abstract
  2. Read the introduction.
  3. Read the conclusion.
  4. Skim the middle, looking at section titles, tables, figures.
  5. Read the whole thing quickly, skipping equations, most figures and tables.
  6. Read the whole thing carefully, focusing on the sections or areas that seem most important.


March 11, 2014, 6:37 p.m.

Exposing project's API



March 11, 2014, 11:13 a.m.

Bussiness communication by tasks

It easier to carry on business flows using tasks, instead messages.

March 10, 2014, 9:11 p.m.

Django templates injection

Main template embedes another template, and asks it for placing special element in it:

{% include 'container.html'
with element_template="element_x.html" %}

Subtemplate embedes passed element:

{% include element_template %}

March 10, 2014, 12:20 p.m.


Extending WorkFlow engine for embeding smaller workflows in larger ones as special states.

March 9, 2014, 10:02 a.m.

Numpy scipy - Use case

Np.array manipulation, model building, approximation and plotting.


March 8, 2014, 11:13 a.m.

Django project architecture - apps over MVC

Project's architecture based on apps and not infected by MVC/MTV. Templates placed in apps. Templates inheritance/include for keeping DRY.

Oh, and one more thing: Making humans edit XML is sadistic!

March 4, 2014, noon

Workflow permissions

Permissions system for views. Depends on:


March 3, 2014, 8:42 p.m.

Eigenvalues testing

Av = λv
vals, vectors = eigs(A)
l = vals[0]
v = vectors[:, 0]

assert allclose(A * l, l * v)


March 2, 2014, 11:39 p.m.

Hooke's law

General tensor form


March 2, 2014, 8:10 p.m.

Arrange different size div blocks

Feb. 28, 2014, 8:43 p.m.

Team leading

The truth about teams is that teams only function well when there is a competent leader that holds the commit rights.


Feb. 26, 2014, 12:55 p.m.

Permissions procedure

The implementation of the program should be completed by defining permissions. It should be done together with the client. The work should by confirmed by the report, which describes how functions are secured in respect to rules in client organisation. It should also include specific cases on which this rules was tested.

The report will be valuable during program updates.

Feb. 25, 2014, 6:25 p.m.

Reclaim memory from sympy



Feb. 14, 2014, 9:08 p.m.

Designing Large Scale Applications

Python DI. Global component's module for decoupling python packages.


Feb. 8, 2014, 10:20 p.m.

C# DI Autofac

No constructors.


Aug. 11, 2013, 4:06 p.m.

Multitasking, rember the GIL

Threading in Python should be used carefully. Mainly for increase responsiveness while IO operation. It should not be used for multicore computing because of GIL. Nowadays in can be seen as an alternative for asynchronous computing. http://www.dabeaz.com/GIL/

Jan. 11, 2012, 8:42 p.m.

Checking computer hardware

$ sudo dmidecode

Jan. 8, 2012, 8:46 p.m.

Increasing the number of open files limit

ulimit -n