Welcome to this website

Computer training, it's been a while I write myself most of the software I need.

This site is designed to show you a free software made of several tools that I named Cyloop : abbreviation for Cyclic loop tools.

Cyloop is a variant of another free software named RRDtool.

RRDtool what is it ?

Let's begin by talking about RRDtool before explaining how Cyloop is different

RRDtool is a set of tools that can record the value of one or more numeric variables at different times, and then generate a graph showing changes over time in the value of one or more variables stored.

RRDtool processes the time linearly. To create a RRDtool blank file, you must specify how often the variable values will be saved and for how many times. However, we can choose to save the values for different time scales.

For instance, you can create a RRDtool file with reasonable size that will record the values of variables as to :
The graphs generated by RRDtool traditionally cover a period of time ranging from one moment more or less distant in the past to the present.

Unless if you create a gigantic RRDtool file able to store variable values every minute or every second for 10 to 100 years (what is never done), this leads to the following limitations :

How is Cyloop different ?

In the case of Cyloop, time is considered as a series of cycles each of which starts after the previous one.

To create a blank cyloop file, you have to define the cycle on which it will work. It may be a period of time based on the calendar (day, week, month, year) or any period of time period chosen.

You must also choose in how many pieces of the same duration (possibly with one second of precision) you will cut the cycle to save data.
In this website, we will talk about moments of the cycle to identify these pieces.

The data that can be stored in a cyloop file are 2 kinds :
When a cycle ends, the next begins, and new data stored in the cyloop file add to the value already stored from previous cycles for the same moment of the cycle.

The graphs generated by Cyloop represent the average value of counters and variables measured over several cycles for each moment of the cycle.

In the simplest case, data from successive cycles are added to the cyloop file. Each cycle is of equal importance in the outcome and after many cycles, the graphics evolve very slowly.

It is also possible for each cycle change to make a weighting calculation (multiplying the values already stored by a coefficient chosen between 0 and 1) to give greater importance to most recent cycles when calculating the average value.

Example using Cyloop

Cyloop for what computers and what operating system ?

Cyloop was written in C and uses only very basic functions of this language. It can therefore work with any computer model and any operating system for which a C language compiler is available.

However, it is highly desirable to use Cyloop on computers equipped with an operating system able to run commands automatically on a periodic scheduled at times, as does the UNIX cron.

Moreover, the command cylgraph starts by generating graphics with format .bmp . If you want the graphics to be stored in another image format (the format .pngis a good choice), it is necessary to have the ImageMagick convert command located on the computer.

The Cyloop project and this website has been made on my free time with no prospect of financial gain.

To work on computer, I use PCs running GNU/Linux. I am opposed to bundling of PCs with Windows (one of the few forms of bundling allowed in practice in France and in many other countries). When a computer is sold with Windows, OS (Home Edition) is about a hundred euros on the total price. If I buy a full desktop computer, I choose a shop that sells it without Windows and my laptops have been purchased when it was possible to find some running GNU/Linux.

Accordingly, this website does not broadcast directly executable Cyloop version for Windows, Mac OS X and other platforms other than GNU/Linux PC. If you want to use Cyloop on other operating systems, you will need to compile yourself sources, or to give me the equipment and the C compiler which would allows me to undertake this work.

This website is multilingual

Being French speaker by birth, I wrote the original Cyloop files specifications, and Cyloop source files with their comments in French

Although knowledge of the language of American (or British version of which it is derived) is convenient to communicate in a lot of countries expecialy with virtually all Scandinavian without knowing their local language, I consider that a website only in English (as many free software websites) or in French and English is not ideal.

On the other hand, to make a website and the user interface and documentation of a multilingual software takes time and online translators available on the web are imperfect. Moreover, those who translate directly from the French (google does not, he uses the English language, a language rich in homonyms as intermediate language) are only limited to very small texts.

For this site, but also for user interface and Cyloop documentation, in addition to English, I chose to add 2 more widespread languages in the world among those who use the Latin alphabet and the same sentence structure than French. With Esperanto (a language internationally oriented, but too few taught), my website should be accessible to a large number of people.

But as human translations are the best, readers of this website are invited to contribute to the work of translation into the language of their choice.