category:Course

esProc External Memory Computing : Principle of Grouping

After data are imported from a data table, we often need to group them as required, or work out grouping and summarizing result. In esProc, groups function is used to compute the result of data grouping and summarizing; or group function can be used to first group the data, then perform further analysis and computation...

2015-01-06 1 0 0

esProc Advanced Coding : Clear Cell Values

In esProc, the storage of cellset variables is ubiquitous. Cell values are convenient references during computation, but they could occupy too much memory. Data can be cleared from cells to reduce memory footprint after they accomplish their mission in computation. It should be particularly noted that, when the interme...

2015-01-05 1 0 0

esProc Program: Modify Table Sequences

Table sequences are universally used in esProc. During data analysis and computing, we often need to add records to a table sequence or delete them from it, or modify the data in it. This article will illustrate the modification and maintenance of the table sequences through operations of adding, deleting and modifying...

2015-01-04 0 0 0

esProc Accesses Databases: Using SQL

In esProc, we can use not only the SQL to retrieve data from databases, but also the preliminary database query results to perform further analyses and operations to solve some complicated problems which are difficult to deal with in SQL alone. 1. Database connection and disconnection When SQL accesses databases, it sh...

2014-12-30 2 0 0

Related Computing in esProc – Sorting and Ranking Data

We often need to sort or rank data during data statistics and analysis. The operations include problems like sort sales records according to the dates and rank the results of salespersons for assessing their performance. 1. Sort and rank members in a sequence In esProc, functions, such as psort, sort, ranki rank, and e...

2014-12-30 1 0 0

esProc Integration & Application: Deploying JDBC

Java programs can call esProc via JDBC. It is necessary for programmers to know how to deploy the esProc JDBC and familiarize themselves with the detailed configuration information. 1. Basic steps The following instructions need to be followed to deploy the esProc JDBC: 1) Load necessary jars Load the jars needed by es...

2014-12-29 2 0 0

esProc Advanced Coding: Creative Usage of Strings

In esProc, strings are not merely a data type; they can also be used as macros or string constants to construct expressions, or employed by eval() function to generate expressions dynamically as needed. 1. Macro Macros in esProc refer to strings for composing expressions, only that these strings are usually generated d...

2014-12-26 1 0 0

esProc Advanced Coding: Code Block

In esProc Getting Started: Types of Cells, we learned that cells in esProc have many types, including constant cell, computational cell, executable cell and comment cell, and etc. The code blocks into which code is written in esProc also have the similar types: computational block, assignment block, executable block an...

2014-12-25 2 0 0

esProc Integration & Application: Command Line

The command line refers to using commands in the form of strings in DOS-like environment to execute programs. All operating systems support the command lines, like the Linux console and the Windows command line window. The file, esprocx.exe, is needed when the command line is used to execute an esProc cellset file. The...

2014-12-24 1 0 0

esProc Accesses Databases: Calling Database Stored Procedures

Besides data tables, store procedures are also very important for a database. esProc can call database stored procedures conveniently. This article will illustrate in detail how to call various stored procedures with db.proc() function in esProc.  1. Call stored procedures without return values Stored procedu...

2014-12-23 2 0 0

esProc Integration & Application: Java Invocation (II)

3. No result or multiple results It is allowed to return no result during calling a cellset file. Take the following cellset file – outputData1.dfx – as an example:   A 1 $(demo) select * from CITIES 2 =A1.select(Arg.pos(left(NAME,1))>0) 3 =file(“Cities.txt”) 4 >A3.export@t...

2014-12-18 3 0 0

esProc Integration & Application: Java Invocation(I)

esProc can be embedded in a Java application. Invoking an esProc cellset program is like  accessing a database via JDBC. During the invocation the cellset program is packaged as a stored procedure, so it is called in the same way as that the latter is called. 1. Basic usage esProc JDBC resembles a database JDBC dr...

2014-12-17 3 0 0

Related Computing in esProc – Data Grouping and Summarizing

It is a common task to group records in a table sequence as needed and to summarize the data in each group during data analysis and statistics. This includes data summarizing like summing up and averaging, as well as the listing of the top n records, and etc. This article will explore how to group and summarize the dat...

2014-12-04 2 0 0

esProc Accesses Databases: Database Configuration

esProc supports a variety of heterogeneous datasources, including the databases. This article will introduce the methods of esProc’s connection to various databases. 1. Configure datasource manager To connect to a relational database, please follow these steps: 1) Click Datasource connection on Tool options menu to ope...

2014-11-26 2 0 0

Related Computing in esProc – Alignment Grouping and Enumeration Grouping

In Related Computing in esProc – Data Grouping and Summarizing, we learned how to group data in a table as needed and to summarize the grouped data. Please note that, in data grouping and summarizing, data will be grouped by a single or multiple fields or an expression in ascending order based on equivalent values. Ali...

2014-11-20 2 0 0