I express huge gratitude to Kirill Guzenko of KirillGuzenko for the help in transfer and preparation of the publicationThe body of the person is a studying subject from the very beginning of human history. The modern scientific directions in anatomy and physiology come from symbiosis of the art and anatomy which arose during a Renaissance era. At the beginning of the 16th century Leonardo da Vinci submitted to one of the first rather detailed and exact sketches of a human body and its structures. In 1543 Vezaly published the well-known textbook De Humani Corporis Fabrica (About a structure of a human body) with beautiful illustrations of it.

Having modern technologies at our disposal, we can submit data on physiology and anatomy in a computable format. By means of Wolfram|Alpha we created for all an opportunity to easily study how separate anatomical structures are connected with each other in a human body, and also to investigate both the whole systems of bodies, and their microscopic components.

2 years, 3 months ago Transfer of a post of Jeffrey Bryant "Stranded on Mars: Exploring Travel on Mars in The Martian". The code given in article can be downloaded here. I express huge gratitude to Kirill Guzenko of KirillGuzenko for the help in transfer and preparation of the publicationNot so long ago according to the popular book The MartianAndy Weir's(Martian)the movie which was released on the second of October was shot. The Martian — the movie about the astronaut Mark Uotni left alone on Mars. Ares's crew of the 3, third piloted flight to Mars, considered that he died during evacuation. The crew during flying away took with itself only fixed assets for rescue and communication. The following piloted weeds to Mars had to take place in four years therefore Uotni had to or think up to himself the plan for a survival during this term, or reconcile and die. Different technical details about conditions and available means, and also about problems which result from use of different things not on their direct assignment are perfectly presented in the book. And these parts give us the excellent chance to investigate adventures of the main character together with Wolfram language.

I think, now that moment when it is necessary to write: CAREFULLY, SPOILERS! From this point in article different aspects of the subject line, its moments and turns will appear and be investigated. And if you do not like to learn some parts of a plot now, then I would recommend to read at first the book, and then to return and read article.

2 years, 3 months ago
Just imagine, we live during a wonderful era, invented computers, forgot how to use mechanical schyota, at every second in a pocket a heavy-duty computer, to steam of generations already grew having pocket calculators, elementary calculations are demanded more and more seldom. Whether long ago you had to do mental arithmetic? Well, say, why not to put couple four or five-digit numbers shopping, then to give to the cashier money to within kopek? You will tell, nonsense all this, waste of time. To whom empty, to whom not empty. I consider that first for maintenance of functionality of a brain it is necessary to use periodically this remarkable functionality, and secondly art to succeed in basic skills makes the person the master.

So, we will start. What can be the most fundamental knowledge for the mathematician? Probably, this that to what we teach children in the first class or even in kindergarten, summing of integral numbers. So, meet game which trains brain performance in the elementary arithmetics:

That well, right there everything relies in reaction and a blind set of numbers

2 years, 3 months agoThe Hola company announces competition on programming on JS with a solid prize fund again:

First place: 1500 USD

Second place: 1000 USD

Third place: 500 USD

Perhaps, we will decide to note someone's extremely original solution a special prize in 350 USD.

If you send someone the link to this tender, having put our address in CC, and this person will take a prize, you receive the same sum, as well as it.

We look for talented programmers therefore authors of interesting solutions will be invited to interviews.

Rules

Some of those who remember our previous tenders were dissatisfied that conditions of tasks were formulated indistinctly, and from the participant it was required "to guess" what we meant. This time the condition is formulated extremely unambiguously, and at the disposal of participants — reference implementation of a solution. That whose code will be the fastest on condition of passing of tests for a correctness will win.

Tender conditions in English are posted on our website. Below — transfer into Russian.

2 years, 3 months ago
Not by my profession article, just I want to warn about one logical vulnerability of our banking system. An essence simple — I satisfied all terms of the contract and earned a penalty, a mark in credit history and a penalty fee 122 rubles. How? under a cat!

2 years, 3 months ago Transfer of a post of Peter Barendse "Surfaces and Solids of Revolution: Using Wolfram|Alpha's "Virtual Potter's Wheel"". The code given in article can be downloaded here. I express huge gratitude to Kirill Guzenko of KirillGuzenko for the help in transfer and preparation of the publication Even before emergence of the modern 3D technology of printing in us there was an opportunity to create objects practically of any form, and the only restrictions for mankind were connected only with the accuracy which we can provide. And on the way of overcoming of these restrictions the various devices capable to make products of very irregular shapes were developed; (before emergence of 3D-printers) emergence of machines with ChPU and a large number of degrees of freedom became the culmination of this process:

Historically the potter's wheel by means of which we had an opportunity to create very exact axisymmetric products of any profile was one of the first similar devices, perhaps. I still perceive it as magic, looking at how the potter creates a curve the hands; how this curve sets a form for all vase through rotation of a wheel:

2 years, 4 months ago
The other day has faced interesting problem which has seemed to me worthy audience of this resource. Condition its following:

"To find the tolerance of mass of candy is maximum by its production that net the box consisting of 12 their pieces was not gone beyond by 310±7 grams in 90% of cases. To consider the distribution law normal."

It is necessary to tell that the condition has not been pulled out from the Internet or spotted on any resource of entertaining tasks, and has come from one very good friend, which on the position the organization and production management engineer on one well-known confectionery. That is the task has quite real origin, and its solution — practical advantage.

I have suggested readers to solve problem independently and has to tell that they have coped with it better me. In the solution I I have made not right assumption.

2 years, 5 months ago
Clearly, why theorists find effective algorithms of solution of problems of some class, and then practicians implement them. But theorists try to prove also that for some problems of effective algorithms (and even in general any algorithms) does not exist. What thus they manage and it is not possible, and why it can be necessary? In lecture it is about "halting problem" and tasks to which it is reduced, about the well-known class NP, and also about simple lower estimates.

Lecture was it is given at Small School of data analysis which Yandex will organize for seniors. The author — Alexander Shen. Has graduated mekhmat from MSU, under the leadership of Vladimir Uspensky, the pupil Kolmogorov, has defended the dissertation "Algorithmic options of concept of entropy". Now is the employee of Institute of problems of information transfer of A.A. Harkevich the Russian Academy of Sciences and Laboratories of the National center of scientific researches of France. Scientific interests: algorithms, Kolmogorov complexity, logic, information theory. Almost all books which Alexander Haniyevich has written about mathematics and to programming, are in free access.

2 years, 5 months ago Discussion transfer "How to peel the labels from marmalade jars using Mathematica?" from the site Mathematica at StackExchange. The code given in article can be downloaded here (~ 31 MB). I express huge gratitude to Kirill Guzenko KirillGuzenko for the help in transfer and preparation of the publicationAs it is possible to select label contents with provided below banks (point of shooting of frame, geometry banks, its contents — all this is not known to us),

to receive something similar — the same label in that look in what it was before it has appeared on bank?

The main idea consists in the following:

We find label.

We find label borders.

We find display of coordinates of pixels of the image to cylindrical coordinates.

We transform the image with use of the found display.

The algorithm offered by us works only for images, in which:

The label is brighter than background (it is necessary for detection of label).

Label rectangular (it is necessary to estimate quality of display).

Bank has to hold vertical position (it is necessary to save simple form of function of display).

Bank has to be cylindrical (it is necessary to save simple form of function of display).

It is necessary to notice that algorithm modular. That is you can add the algorithm of detection of label which will not demand dark background, or can write the function of assessment of quality of display which will allow to work with oval or polygonal labels.

The algorithm which has turned out finally works completely automatically (however there is option of manual task of borders banks), that is takes the source image then issues the image with grid and label.

2 years, 5 months ago
It is well-known that it is impossible to earn on Forex. Changes of exchange rates have accidental character, and the commission of the broker reduces probability of positive final earnings, often doing it absolutely unattractive, ― below, than in casino, for example. Nevertheless, I support myself and the projects only for the account Forex three years, I went to it about 7 years and, remembering this way, have decided to write note for those who is attracted by this antiscientific possibility of earnings.

Graalyakh, sold on the Internet, will be a question of high-frequency trade and not of "risk-free" attachments in mythical TOP-20 the best traders about wonderful. Only hardcore: we perform numerous trade operations, someone manually, someone ― automatically, and we receive as a result of these operations positive gain of the account at statistically significant number of transactions.