Statistics and Causation
Let’s consider the statistical relationship collected over 50 USA startups: between R&D cost and the profit (data taken from 50_Startups.csv): Note: values in both x-axis and y-axis are in units of 1000$ The Pearson correlation coefficient is 0.97, very strong relationship between R&D and Profit. What’s about the causation? Does High Cost of R&D […]
Git Commands in Single Figure
How Git commands work from ByteByteGo.com Slava23+ years’ programming and theoretical experience in the computer science fields such as video compression, media streaming and artificial intelligence (co-author of several papers and patents). the author is looking for new job, my resume Donate videonerd.website
Banach-Tarski Theorem and Philosopher’s Stone
Banach-Tarski Theorem and Philosopher’s stone or How Become Billionaire Banach-Tarski Theorem says: “It is possible to decompose a solid sphere into a finite number of pieces, which can then be reassembled to create two spheres identical to the original” In other words, if you have a golden brick, then you can decompose it in a […]
Python Script To Get Info on Cookies
A cookie is a small piece of data that the server sends in a Set-Cookie header as a part of the response in HTTP (or HTTPS). The client stores cookies locally and includes them in any future requests that are sent to the server. Thus, servers use cookies to track a client, its history etc. […]
Python Script To Download RFC Document
All internet protocols are specified in a special document, called RFC, moreover all RFCs are located at https://www.ietf.org/rfc/, for example UDP is specified by RFC 768. I wrote a script to download RFC document according to its number, download_rfc.py Usage: download_rfc.py [options] Options: -n RFC number -o output rfc-file in txt-format […]
Stability of System Linear Equations and Condition Number
Let’s consider the system of linear equations in the matrix form: A x = b If we make tiny changes in the vector ‘b’ and the solution ‘x’ will change a little then the matrix ‘A’ is called stable. Otherwise, if any tiny change of the vector ‘b’ provides strongly different solution ‘x’, then […]
Distinction between Pearson and Spearman Correlations
Pearson correlation measures a linear relationship between X and Y, while Spearman correlation estimates a non-linear relationship. In some cases, the relationship between X and Y (e.g. Bitrate and Quality) is strictly non-linear: taken from https://avichawla.substack.com/p/the-limitation-of-pearson-correlation The following Python script shows how to compute Pearson and Spearman correlation coefficients: import numpy as […]
Approximation of (1-k)^t when ‘k’ is small and ‘t’ is big
when ‘k’ is small and ‘t’ is big For example, let k=0.01 and t =100 Slava23+ years’ programming and theoretical experience in the computer science fields such as video compression, media streaming and artificial intelligence (co-author of several papers and patents). the author is looking for new job, my resume Donate videonerd.website
What are three main differences between Marx and Lenin?
1) Marx was an armchair theorist, while Lenin was a practitioner and in the end took power in Russia. 2) Marx developed his theory watching 19th-century industrial societies in Western Europe, while Lenin adapted Marxism to the realities of 20th-century Imperial Russia, where peasants constituted 4/5th of the population. 3) Marx was a lousy party […]
The Size of Tip in Restaurant
Famous social psychologist Bibb Latante visiting hundreds of Parisian restaurants empirically inferred the following formula, how the size of the tip depends on a number of people sitting at table: p = k Nt where t<1, N is the number of guests at table p – tip k – coefficient (= quality of service) […]