The series of articles on esProc charts discussed how to use chart elements in plotting algorithms to make charts. Besides writing plotting algorithms, we can use a number of built-in ready-made graphs to quickly plot common styles of charts.
There are four types of ready-made graphs (Column graph, Line graph, Pie grap...
2015-06-16 67 0
It’s hard to create reports with unconventional layouts directly with functions provided by a reporting tool. However, if the data for building such a report can be beautifully prepared, the difficulty could be considerably reduced.
esProc(free edition is available) is an expert at handling this data preparation. It pr...
2015-06-15 64 0
Sometimes you need to query a big text file, instead of the database. In those cases, you need to retrieve the file in a stream style to perform the query algorithm, in which parallel processing is needed to improve the computing performance. As Java lacks the class library for doing these, you have to use hardcoding t...
2015-06-12 43 0
This article aims to test esProc performance of retrieving files and compares it with the result got by using Oracle JDBC.
The test data is some order records saved in the orders.b file. Import the file with esProc and its content would be like this:
ORDERID CLIENT SELLERID AMOUNT ORDERDATE NOTE...
2015-06-11 43 0
This article aims to test esProc performance in processing files concurrently, based on filter, group and aggregate operations and comparison with Oracle.
Test data includes tables of ordering information of different years. With esProc, files (Orders2009.b, Orders2010.b, Orders2011.b and Orders2012.b) of binary format...
2015-06-10 60 0
It is not uncommon in actual business to tackle complex computational problems by composing dynamic SQL. The skill has generated a lot of discussion across online IT forums. Here are links to some of the questions around it:
2015-06-09 54 0
This article focuses on testing performance of esProc’s handling of file traversal, using commonly used group and aggregate operations as well as query and filter operations. The performance test will include evaluation of the influence of using multithreads, and comparison between esProc approach and Oracle counterpar...
2015-06-05 48 0
In some cases, data must be stored in the file system, rather than in a database. That requires handling file-based data computing manually. Since Java lacks the related class library, you have to hardcode the structured file computing, which produces complicated and unreadable code.
Yet, you can make up for this defic...
2015-06-04 69 0
In esProc, it is common to add text to various charts. The text is plotted and positioned with the text element, and has its own style compared with text working with other chart elements (though the latter’s properties can be adjusted in a similar way).
The text element has a relatively simple functi...
2015-06-03 77 0
24-point game is a common intellectual game, which can be played with cards without jokers. The rule is to draw four random cards and manipulate the four numbers to get the result 24 using four arithmetic operations: addition, subtraction, multiplication and division. In card playing, J, Q, K correspond numbers 11, 12 ...
2015-06-03 44 0
For a given system of linear equations in n unknowns, there must be n equations to form the system. e.g.:
Well, how do you solve this system of linear equations with n variables with esProc? First, the system of equations should be written in a standard form, and parameters are fill...
2015-06-02 75 0
Used only in polar coordinates, the sector element is usually for plotting a pie chart. Here we’ll explain how it is employed and its properties.
1. Data properties
Through the following pie chart for displaying vault results, we’ll discuss the basics of plotting the sector element.
2015-06-01 59 0
Among lots of chess puzzles, the problem of the eight queens is the most well-known example. Eight queens must be placed on a 8×8 chessboard so that no queen attacks any others. Well, how many solutions are there?
A queen attacks any other queen that sits on the same row, column or diagonal. Thus a solution requi...
2015-05-29 39 0
The column element is frequently used in plotting various charts. We’ve made some studies about it in esProc Charts: Coordinate Axes through examples. Here we’ll illustrate the setting of its properties and their roles.
1. Data properties
The plotting algorithm below for plotting a clustered column chart of gym results...
2015-05-28 47 0
A link-relative ratio is a percentage got by comparing the data of current period and that of the previous period. Usually the interval between the two periods is a month (sometimes an hour, a day, a week and a quarter). The link-relative ratio of April is computed by dividing, for example, its sales amount by that of ...
2015-05-28 46 0