Matrex 1.3 coding has been finished.
I'm now testing it and updating the documentation.
Hopefully I'll release it at the end of september.
I'm now testing it and updating the documentation.
Hopefully I'll release it at the end of september.
Sunday, August 31, 2008
Friday, August 29, 2008
Callbacks
A Matrex project consists in a network of matrices and functions (let's forget about charts, presentations and timers).
They are connected together by the relations:
One peculiar property of this network is that it does not have loops. In mathematics it is representable as a simple graph.
This means that a matrix cannot be, directly or through other functions and matrices, input and output of the same function.
This is a good property, because it guarantees that, if the calculation of each single function terminates in a finite time, the calculation of the whole project terminates in a finite time.
In other words, the calculation of the project cannot contain an infinite loop.
In the upcoming version 1.3 I made an exception to this property, to solve the following problem:
I added a new solver function template to Matrex, that finds the minima of functions.
To use a solver, you need to pass to it the function you want to minimize.
In a programming language, you pass the function to mimimize to the solver function as a callback function (or a closure).
But how I did this in Matrex?
In Matrex, a programming language's function is equivalent to a network of functions and matrices, which, seen as a black box, has input and output matrices:
This block of functions and matrices can be equivalent to a callback function, with a trick:
Here is a picture showing the concept:
In this way the caller, by changing the content of one of its input matrices recalculates the callback block.
When the callback block executes, it updates the content of its output matrices. But one of those is a input matrix of the caller, therefore the caller is recalculated.
Caller and callback block execute each other until the caller decides to stop and does not change the content of the output matrix that it has in common with the callback block.
But when does the caller decide to stop? This depends by the caller code.
The solver I added In Matrex is Nelder Mead (sys.mathstat.optimization.neldermead), an implementation of the direct search algorithm, a simplex optimization algorithm (it uses the Apache Commons Math library).
At each step of the solving process the solver needs to call a function to calculate the cost of the current solution. The cost calculation function is our callback function.
The following picture shows the solver, the cost calculation function and their input and output matrices:
x is the callback matrix of the solver. It is both output matrix of the solver and input matrix of the cost calculation function.
When the content of x is changed, the cost calculation function is fired and it calculates the cost matrix, which is input of the solver.
The solver is executed and produces a new content for the x matrix, therefore firing the cost calculation function, until the cost is good enough to stop. At this point it stops changing the content of x and writes the final solution in the result matrix.
What I learned writing the Nelder Mead solver template is that one has to write the caller code carefully making always sure that the mutual execution of caller and callback function stops at a certain point, in a way or the other. For example a solver must stop after a certain number of iterations, even if it does not converge.
Adding callbacks in Matrex required some changes in the code:
They are connected together by the relations:
- The matrix Mi is input parameter of the function Fj
- The matrix Mi is output (result) of the function Fj
One peculiar property of this network is that it does not have loops. In mathematics it is representable as a simple graph.
This means that a matrix cannot be, directly or through other functions and matrices, input and output of the same function.
This is a good property, because it guarantees that, if the calculation of each single function terminates in a finite time, the calculation of the whole project terminates in a finite time.
In other words, the calculation of the project cannot contain an infinite loop.
In the upcoming version 1.3 I made an exception to this property, to solve the following problem:
I added a new solver function template to Matrex, that finds the minima of functions.
To use a solver, you need to pass to it the function you want to minimize.
In a programming language, you pass the function to mimimize to the solver function as a callback function (or a closure).
But how I did this in Matrex?
In Matrex, a programming language's function is equivalent to a network of functions and matrices, which, seen as a black box, has input and output matrices:
This block of functions and matrices can be equivalent to a callback function, with a trick:
- the output of the callback block and the input of the caller must have one matrix in common
- the output of the caller and the input of the callback block must have one matrix in common
Here is a picture showing the concept:
In this way the caller, by changing the content of one of its input matrices recalculates the callback block.
When the callback block executes, it updates the content of its output matrices. But one of those is a input matrix of the caller, therefore the caller is recalculated.
Caller and callback block execute each other until the caller decides to stop and does not change the content of the output matrix that it has in common with the callback block.
But when does the caller decide to stop? This depends by the caller code.
The solver I added In Matrex is Nelder Mead (sys.mathstat.optimization.neldermead), an implementation of the direct search algorithm, a simplex optimization algorithm (it uses the Apache Commons Math library).
At each step of the solving process the solver needs to call a function to calculate the cost of the current solution. The cost calculation function is our callback function.
The following picture shows the solver, the cost calculation function and their input and output matrices:
x is the callback matrix of the solver. It is both output matrix of the solver and input matrix of the cost calculation function.
When the content of x is changed, the cost calculation function is fired and it calculates the cost matrix, which is input of the solver.
The solver is executed and produces a new content for the x matrix, therefore firing the cost calculation function, until the cost is good enough to stop. At this point it stops changing the content of x and writes the final solution in the result matrix.
What I learned writing the Nelder Mead solver template is that one has to write the caller code carefully making always sure that the mutual execution of caller and callback function stops at a certain point, in a way or the other. For example a solver must stop after a certain number of iterations, even if it does not converge.
Adding callbacks in Matrex required some changes in the code:
- The callback matrix is special: adding a function that has a callback output matrix requires that this matrix is already in the project (it is the input matrix for the callback block).
- Functions that have callback output matrices are not calculated when the project is loaded.
Calculating them only once would leave them incomplete (for a solver this means to calculate only one step).
Calculate them until they stop would be a risk. Better to leave to the user the responsability to calculate them.
Saturday, July 26, 2008
Test test test
Matrex is a project that gets tested manually by me before it is released.
For this purpose I use a check list.
I run Matrex and I verify that the operations listed in the check list, like adding a matrix, adding a function... are executed correctly and don't produce side effects.
Matrex is also tested by some of its user, but generally the users test it after a new version has been released. This is not very satisfactory, even if it allows me to release corrective versions.
To reduce the possibility that a version is released with bugs, I started, from version 1.2, to add some unit testing.
In the incoming release 1.3 unit testing will be a main concept:
For this purpose I use a check list.
I run Matrex and I verify that the operations listed in the check list, like adding a matrix, adding a function... are executed correctly and don't produce side effects.
Matrex is also tested by some of its user, but generally the users test it after a new version has been released. This is not very satisfactory, even if it allows me to release corrective versions.
To reduce the possibility that a version is released with bugs, I started, from version 1.2, to add some unit testing.
In the incoming release 1.3 unit testing will be a main concept:
- the tested classes are at this moment more than 160, covering almost all Matrex template functions and a good section of the application code.
- I'm checking the possibility to have also some GUI classes tested, using the SWTBot GUI unit testing tool.
- Improve the quality of the code.
- Help developers understand the code of Matrex.
- Reduce the possibility of regression bugs.
Saturday, June 21, 2008
Changes in the main window
Version 1.3 changes something in the main window:
- The buttons that are highlighted with a green rectangle hide or show trees. For example the first button hides the Matrix tree. Clicking it once again the Matrix tree is displayed again.
The second button toggles the Function tree visibility, the third the Presentation tree, the 4th the Chart tree and 5th the Timer tree. - On the top of each tree, together with the tree menu, there is a search bar, highlighted with a red rectangle.
Writing a part of the name/package of the item to search (matrix, function...) and clicking on the green arrow button, the next item with name-package containing that text is selected and showed in the tree.
For example the text ding.pri finds the item trading.price.
Friday, June 06, 2008
Exception stack trace for final users
In Matrex, like in other programs, it is not always possible to show a simple message box when an error occurred.
Sometimes what I have is an exception occurred deep down in the code, may be in a library.
Nevertheless something has to be shown to the user to let him understand that an error has occurred and give him all the available information to decide what to do.
A classic exception stack trace is not an option: together with the exception text it contains a lot of information to localize the code that generated the exception.
This information, that is precious for the developer, is probably unuseful and confusing for the final user.
For this reason I wrote a small function that transform the exception in a string that contains only the texts of the exception and of all contained (cause) exceptions. Here is the code:
public static String flatException(Throwable e)
{
StringBuilder b = new StringBuilder();
while(e != null)
{
b.append(e.getMessage()).append('\n');
e = e.getCause();
}
return b.toString();
}
Even if the number of contained exception is large, the message is generally simple and gives immediately an idea of what happened.
This is not intended as a substitute of the classic stack trace, which is written in the application log file so that if needed it can be examined by the developer.
Sometimes what I have is an exception occurred deep down in the code, may be in a library.
Nevertheless something has to be shown to the user to let him understand that an error has occurred and give him all the available information to decide what to do.
A classic exception stack trace is not an option: together with the exception text it contains a lot of information to localize the code that generated the exception.
This information, that is precious for the developer, is probably unuseful and confusing for the final user.
For this reason I wrote a small function that transform the exception in a string that contains only the texts of the exception and of all contained (cause) exceptions. Here is the code:
public static String flatException(Throwable e)
{
StringBuilder b = new StringBuilder();
while(e != null)
{
b.append(e.getMessage()).append('\n');
e = e.getCause();
}
return b.toString();
}
Even if the number of contained exception is large, the message is generally simple and gives immediately an idea of what happened.
This is not intended as a substitute of the classic stack trace, which is written in the application log file so that if needed it can be examined by the developer.
Sunday, June 01, 2008
Fit Columns
A new feature that will be released with version 1.3 is the possibility to fit the width of the columns of the table in a matrix viewer or in a presentation viewer.
This has been a problem from the moment I started to use virtual tables for the two viewer.
Virtual tables have the advantage that they can show tables with a huge amount of rows (> 10000) instantly, because they load only the rows of the table that are displayed in that moment, not the whole table.
As a side effect, there is no way to automatically set the width of the columns so that they can fit the text displayed in the columns' cells.
Because of this, before version 1.3 the use has to manually change the width of the columns.
In version 1.3 I added a menu in the two viewers, called Fit Columns:
This menu calls a function that takes a sample of the table's content: a fixed amount of rows. It measures the lengths of the texts contained in the cells of these rows, and with them it calculates an estimation of the columns' width. Then sets the columns' with to this value.
In conclusion there is no automatic columns' width calculation. The user decides when to calculate them. And that is a good thing, because if the matrix or the presentation change (because matrices get recalculated in Matrex), he can click the menu when he wants to update the width accordingly.
Virtual tables have the advantage that they can show tables with a huge amount of rows (> 10000) instantly, because they load only the rows of the table that are displayed in that moment, not the whole table.
As a side effect, there is no way to automatically set the width of the columns so that they can fit the text displayed in the columns' cells.
Because of this, before version 1.3 the use has to manually change the width of the columns.
In version 1.3 I added a menu in the two viewers, called Fit Columns:
This menu calls a function that takes a sample of the table's content: a fixed amount of rows. It measures the lengths of the texts contained in the cells of these rows, and with them it calculates an estimation of the columns' width. Then sets the columns' with to this value.
In conclusion there is no automatic columns' width calculation. The user decides when to calculate them. And that is a good thing, because if the matrix or the presentation change (because matrices get recalculated in Matrex), he can click the menu when he wants to update the width accordingly.
Thursday, May 29, 2008
High Low charts
One of the new features that will come with version 1.3 are the High Low charts.
It is a kind of financial charts that shows the evolutions of the quantities high, low, open, close and volume in a time period.
As all the other charts in Matrex, the charts are built using the JFreeChart library.
They can be shown in two variants: candlestick chart (top chart in the following picture) or high low chart (bottom chart). The picture shows the chart viewer for two high low charts that share the domain axis:
To build this kind of chart there is a special editor. In the following picture we show the editor for the two charts in the viewer.
There is one row in the table for each chart in the viewer. The values of high, low, open, close, volume are 1-column matrices in the same Matrex project.
The time period that defines the domain axis can be defined in two ways:
which shows the values for the first chart in the viewer: it is a candlestick chart, with the time period composed by an interval [start,step] and has all the values (high,low,open,close,volume) assigned to 1-column matrices of the project.
As all the other charts in Matrex, the charts are built using the JFreeChart library.
They can be shown in two variants: candlestick chart (top chart in the following picture) or high low chart (bottom chart). The picture shows the chart viewer for two high low charts that share the domain axis:
To build this kind of chart there is a special editor. In the following picture we show the editor for the two charts in the viewer.
There is one row in the table for each chart in the viewer. The values of high, low, open, close, volume are 1-column matrices in the same Matrex project.
- it can be a 1-column matrix containing date/times.
- it can be an interval defined as [start,step]
which shows the values for the first chart in the viewer: it is a candlestick chart, with the time period composed by an interval [start,step] and has all the values (high,low,open,close,volume) assigned to 1-column matrices of the project.
Friday, April 04, 2008
SWT Web installer RC1 released
The documentation is in the SWT Web Installer site, and you can download it from SourceForge.
Please report any bugs/problems/feature requests.
Moreover, there is a new version of the client/server architecture document in the Matrex site.
The main change is that the document considers also sequences of operations on the project that need to be executed atomically (transactions).
Please report any bugs/problems/feature requests.
Moreover, there is a new version of the client/server architecture document in the Matrex site.
The main change is that the document considers also sequences of operations on the project that need to be executed atomically (transactions).
Monday, March 31, 2008
Status
SWT web installer
SWT web installer is almost ready to be released.
I tested it and wrote the documentation. It just needs the final touches.
I think it will be released during this week as version 1.0 beta.
License is LGPL 3.0.
ISQL
I made a library of ISQL, which I will release as soon as possible.
ISQL can be actually using separately from Matrex.
It is just to call a function with, as parameters, the SQL query and the input and output arrays.
I think it can be very interesting for people that wants to use SQL on arrays in memory.
Also in this case the license will be GPL 3.0-
Matrex
There will be a version 1.3 of Matrex.
The idea is to include in this version the last changes made to the source code of Matrex:
I'm also working to plan version 2.0 of Matrex. I tested an example of RMI callbacks and I've found that it works very well. I will soon publish a new document about the future Matrex Client/Server architecture.
SWT web installer is almost ready to be released.
I tested it and wrote the documentation. It just needs the final touches.
I think it will be released during this week as version 1.0 beta.
License is LGPL 3.0.
ISQL
I made a library of ISQL, which I will release as soon as possible.
ISQL can be actually using separately from Matrex.
It is just to call a function with, as parameters, the SQL query and the input and output arrays.
I think it can be very interesting for people that wants to use SQL on arrays in memory.
Also in this case the license will be GPL 3.0-
Matrex
There will be a version 1.3 of Matrex.
The idea is to include in this version the last changes made to the source code of Matrex:
- new classloader and plugins structure
- SWT web installer to install SWT from internet
- separated ISQL library
I'm also working to plan version 2.0 of Matrex. I tested an example of RMI callbacks and I've found that it works very well. I will soon publish a new document about the future Matrex Client/Server architecture.
Thursday, March 13, 2008
The SWT Web Installer
You wrote this nice SWT application and you want to release it.
And you realized it is not so easy, especially if the user has to install it himself.
Yes, because there is a different SWT version for each platform: a version for Windows, a version for Mac OSX, a version for Linux... not only, but also different versions for 32 and 64 bits.
What you do? You build a setup file for your application for each platform?
With these thoughts, I wrote a library that does the job for you.
It is called OS dependent installer (osdepinstaller).
You call it from your installer or from your application and it installs the right SWT version for the platform where your application is installed.
It works in this way:
For example if the automatic choice of the platform does not work, the user is asked to do the choice manually.
A principle of osdepinstaller is to give all the information about what it is doing. In this way the user can continue manually if for some reason the library is not able to continue.
Since osdepinstaller cannot work without internet, and it can happen that the internet can be accessed only through a firewall or a proxy, the system checks with the user if there is a proxy and, in this case, if the proxy needs authorization.
To get data from the user and to show the status osdepinstaller uses by default the console (since it is normal that your application does not have a GUI until osdepinstaller has finished), but it can be easily adapted to other solutions.
Also, osdepinstaller is not only for SWT: it can be used for any library the is platform dependent.
Osdepinstaller is still in test, but you can download a test version and check the code.
I will use osdepinstaller to let the user install SWT with the generic installer of Matrex.
And you realized it is not so easy, especially if the user has to install it himself.
Yes, because there is a different SWT version for each platform: a version for Windows, a version for Mac OSX, a version for Linux... not only, but also different versions for 32 and 64 bits.
What you do? You build a setup file for your application for each platform?
With these thoughts, I wrote a library that does the job for you.
It is called OS dependent installer (osdepinstaller).
You call it from your installer or from your application and it installs the right SWT version for the platform where your application is installed.
It works in this way:
- it loads from the internet a file containing a list of links to download the SWT library from, one for each platform.
- It checks the platform in which it is installed (two properties, os.type and os.arch).
- it gets the link for that platform
- it downloads the SWT library (it is a zip file)
- it unzips the SWT library in a specific directory
For example if the automatic choice of the platform does not work, the user is asked to do the choice manually.
A principle of osdepinstaller is to give all the information about what it is doing. In this way the user can continue manually if for some reason the library is not able to continue.
Since osdepinstaller cannot work without internet, and it can happen that the internet can be accessed only through a firewall or a proxy, the system checks with the user if there is a proxy and, in this case, if the proxy needs authorization.
To get data from the user and to show the status osdepinstaller uses by default the console (since it is normal that your application does not have a GUI until osdepinstaller has finished), but it can be easily adapted to other solutions.
Also, osdepinstaller is not only for SWT: it can be used for any library the is platform dependent.
Osdepinstaller is still in test, but you can download a test version and check the code.
I will use osdepinstaller to let the user install SWT with the generic installer of Matrex.
Monday, March 10, 2008
Matrex 1.2 for MacOSX alternative setup
I've got some one reporting me that the Matrex 1.2 version for Mac OSX does not install perfectly on all Macs.
The problem is that sometimes after the setup Matrex does not look like an application but like a simple java folder.
Surely you can open a terminal and run the shell script (the batch file) from there, but this is not really an intuitive way of running it!
I use IzPack to install my software and IzPack claims to be able to install also on Mac OSX, even if from some messages in mailing lists it seems that there could be some problems.
I tried to see what I can do.
First I will modify the shell script so that it can be called from everywhere (an initial statement to let it use the current directory as starting directory).
Then I will update Izpack to the last version (3.11).
But one thing that I would really like to do is to create a MacOSX application bundle containing the Matrex files.
The application bundle is the natural way applications are installed on MacOSX.
To do this you need:
So, if someone has a Mac and wants to help me to build this application bundle and to test it, can he please let me know?
The problem is that sometimes after the setup Matrex does not look like an application but like a simple java folder.
Surely you can open a terminal and run the shell script (the batch file) from there, but this is not really an intuitive way of running it!
I use IzPack to install my software and IzPack claims to be able to install also on Mac OSX, even if from some messages in mailing lists it seems that there could be some problems.
I tried to see what I can do.
First I will modify the shell script so that it can be called from everywhere (an initial statement to let it use the current directory as starting directory).
Then I will update Izpack to the last version (3.11).
But one thing that I would really like to do is to create a MacOSX application bundle containing the Matrex files.
The application bundle is the natural way applications are installed on MacOSX.
To do this you need:
- a .icns file, that contains the application icon.
- a way to generate a .dmg file, which is an autoinstalling disk image containing the application bundle.
So, if someone has a Mac and wants to help me to build this application bundle and to test it, can he please let me know?
Wednesday, February 27, 2008
List file class loader
Matrex is composed by several jars:
Here is the typical content of a batch file starting Matrex (it uses the two variables MATREX_CP and LIB_CP):
This approach has several problems:
In these days I worked on a new approach. The idea is to have 3 files containing the list of jars needed to start Matrex:
matrex_api.jar
matrex_fun.jar
matrex_gui.jar
To load these files and to load the jars listed in them, Matrex uses a custom class loader, TextFilesClassLoader.
The start class of Matrex is now called MatrexLoader.
MatrexLoader loads the main class of Matrex, Start, using TextFilesClassLoader as class loader.
Since Start all the other classes of Matrex (included the ones in the library) are loaded, directly or indirectly, from Start, they all use the same class loader used by Start, TextFilesClassLoader.
In this way it has been also possible to write a special Matrex GUI dialog, PluginsDialog, to update the content of plugins.cld:
This is much easier than to change manually the batch file.
- The Matrex jars: api, gui, fun.
- The libraries used by Matrex, for example SWT, jfreechart.
- The plug-ins, for example the library to connect Matrex to Matlab.
Here is the typical content of a batch file starting Matrex (it uses the two variables MATREX_CP and LIB_CP):
MATREX_CP=matrex_api.jar:matrex_fun.jar:matrex_gui.jar
LIB_CP=freehepj3d.jar:jython.jar:commons-math-1.1.jar:jfreechart-1.0.8a.jar:jcommon-1.0.12.jar:jxl.jar:lucene-core-2.0.0.jar:swt/swt.jar:antlr-runtime-3.0.1.jar:javacsv.jar:net.sf.paperclips_1.0.2.jar
java -Djava.library.path=swt -Djava.util.logging.config.file=logging.properties -classpath $MATREX_CP:$LIB_CP matrex.gui.Start $1
This approach has several problems:
- It is not readable, and it becomes less readable adding more libraries.
- If the user wants to add a plug-in, he has to edit the batch file. This is unconfortable, because the user needs to learn the syntax of the batch file, and dangerous: if the user does a small mistake changing the batch file the program does not start.
- you need to have one copy of this batch file for each platform in which Matrex is released (Windows, Linux, MacOSX...).
In these days I worked on a new approach. The idea is to have 3 files containing the list of jars needed to start Matrex:
- matrex.cld containing the main Matrex jars
- libraries.cld containing the libraries used by Matrex
- plugis.cld containing the plug-ins (it is empty when Matrex is installed)
matrex_api.jar
matrex_fun.jar
matrex_gui.jar
To load these files and to load the jars listed in them, Matrex uses a custom class loader, TextFilesClassLoader.
The start class of Matrex is now called MatrexLoader.
MatrexLoader loads the main class of Matrex, Start, using TextFilesClassLoader as class loader.
Since Start all the other classes of Matrex (included the ones in the library) are loaded, directly or indirectly, from Start, they all use the same class loader used by Start, TextFilesClassLoader.
In this way it has been also possible to write a special Matrex GUI dialog, PluginsDialog, to update the content of plugins.cld:
This is much easier than to change manually the batch file.
Wednesday, February 06, 2008
Matrex functions unit testing
I added a small chapter at the end of the function coding document about the Matrex functions code unit testing.
Before version 1.2 some of the Matrex functions had JUnit unit testing, but it was very limited.
In version 1.2 I had to write the code for the ISQL function template, which is very complex compared to the other templates.
So I needed to test it well.
For this reason I wrote some unit testing help classes (for JUnit) that I grouped under the package matrex.item.test.
These classes can be used for the unit testing of any Matrex function template.
With these classes unit testing of matrex functions becomes very easy. For standard function templates it is a matter of minutes to write a test case.
Give a look to them!
Before version 1.2 some of the Matrex functions had JUnit unit testing, but it was very limited.
In version 1.2 I had to write the code for the ISQL function template, which is very complex compared to the other templates.
So I needed to test it well.
For this reason I wrote some unit testing help classes (for JUnit) that I grouped under the package matrex.item.test.
These classes can be used for the unit testing of any Matrex function template.
With these classes unit testing of matrex functions becomes very easy. For standard function templates it is a matter of minutes to write a test case.
Give a look to them!
Monday, February 04, 2008
Matrex 1.2 released
Finally Matrex 1.2 has been released!
The big step forward of this version is the new ISQL module.
The ISQL module is a function template to apply SQL queries to vectors in a Matrex project.
It is therefore possible:
As far as I know, no other spreadsheet application allows something similar.
Other enhancements are:
The big step forward of this version is the new ISQL module.
The ISQL module is a function template to apply SQL queries to vectors in a Matrex project.
It is therefore possible:
- to apply filters on parts of the vectors
- to order the elements of the vectors
- to aggregate them
As far as I know, no other spreadsheet application allows something similar.
Other enhancements are:
- Print matrices and presentations.
- Export matrices and presentations to csv and xls.
- Import data from database, using an SQL query.
- Menus to remove multiple items, duplicate matrices and functions, add function from a matrix (the function will have the matrix as first argument).
- A summary step for the expression parser.
- Possibility to change the colors of the windows headers.
Wednesday, January 23, 2008
Pre-release of Matrex 1.2 to test
I'm in the test phase of the version 1.2 of Matrex.
If someone wants to test this pre-release version himself, he can:
Thanks
If someone wants to test this pre-release version himself, he can:
- download the pre-release generic setup
- install it
- install the SWT library for his platform in the swt directory of the installation
- use one of the matrix_generic.* files in doc/batch_files to launch Matrex
- The new ISQL (internal SQL) module. There is a document about it in the setup.
- New import and export modules.
Thanks
Sunday, January 13, 2008
Version 1.2 status
Coding and documentation are finished.
I'm now working on an example project for the ISQL module.
After that I will terminate the test of the system and release it.
There will be a version for:
The generic version does not install SWT. You have to get it and unzip it yourself under the swt directory.
I'm now working on an example project for the ISQL module.
After that I will terminate the test of the system and release it.
There will be a version for:
- Windows 32 bits
- Linux 32 bits
- Mac OSX
The generic version does not install SWT. You have to get it and unzip it yourself under the swt directory.
Wednesday, December 19, 2007
Status
Today I finally released matrexjruby 1.0.2 (you can find it in the Matrex download page). It took some time to do the final test because of the frenetical work on Matrex 1.2.
I'm now working on the last pieces of code of Matrex 1.2, since ISQL has now been tested and I consider it finished:
I'm now working on the last pieces of code of Matrex 1.2, since ISQL has now been tested and I consider it finished:
- the code that allows to add a function from the matrix tree using as first matrix parameter the selected matrix.
- the code that allows to create an item from the item selection dialog box.
Thursday, November 01, 2007
MatrexJRuby
I updated the code of the adapter matrexjruby, which was still based on JRuby 0.9.
Now it works with JRuby 1.01.
Only a few fixes was needed (use the Ruby class instead of the IRuby interface, let the JRuby classes inherit from an abstract class instead of the IFunction interface).
Matrexjruby is used to write the scripts that are the "code" of the Matrex function templates.
I just need some final test and I will publish it as version 1.02.
Now it works with JRuby 1.01.
Only a few fixes was needed (use the Ruby class instead of the IRuby interface, let the JRuby classes inherit from an abstract class instead of the IFunction interface).
Matrexjruby is used to write the scripts that are the "code" of the Matrex function templates.
I just need some final test and I will publish it as version 1.02.
Tuesday, October 30, 2007
See the light
Finally!
I 've got stock with the internal sql module for a long while, I'm now able to see some results.
The biggest problem derived from the fact that I made the case... when... then... clause originally too complex (the when clause was too general).
Now I'm able to run some "select ... from ... where..." queries (without group by or order by clauses).
The code is on CVS under the package matrex.fun.sys.sql , so you can give a look yourself if you like.
It looks like it will not take so long before I have an implementation of the group by clause (together with the aggregate functions).
Still some doubts about the order by clause (allow order by or only order by ?).
So, now we should be closer to version 1.2, if nothing comes in the way.
I 've got stock with the internal sql module for a long while, I'm now able to see some results.
The biggest problem derived from the fact that I made the case... when... then... clause originally too complex (the when clause was too general).
Now I'm able to run some "select ... from ... where..." queries (without group by or order by clauses).
The code is on CVS under the package matrex.fun.sys.sql , so you can give a look yourself if you like.
It looks like it will not take so long before I have an implementation of the group by clause (together with the aggregate functions).
Still some doubts about the order by clause (allow order by
So, now we should be closer to version 1.2, if nothing comes in the way.
Thursday, October 04, 2007
Antlr for the SQL module
To build the internal SQL module for Matrex I decided to work in the following way:
Antlr has the following advantages compared to the other parsers:
The reasons are probably:
Simple, right? Wrong. Here are the problems for this approach:
- Write a parser that converts the SQL expression in an internal object structure
- Write the code that applies the parsed SQL to the matrices/vectors arguments of the SQL function.
Antlr has the following advantages compared to the other parsers:
- More people use it (at least it looks like)
- The parse result can be code in different languages (Java, C#, python...) that can be useful if I want to port the same grammar to other projects
- Together with the library you can download a graphical application called AntlrWorks to interactively test and debug your grammar. AntlrWorks is a very good tool, that let you find errors in your grammar before you start to use it.
The reasons are probably:
- my inexperience in terms of parsers/lexers
- some confusion and some holes in the free documentation
Simple, right? Wrong. Here are the problems for this approach:
- Antlr is in version 3 now (is normally called v3). The example grammars are most made for version 2 (2.7.x). Altough v2 and v3 grammars look very similar, to convert a v2 grammar to a v3 one is not easy.
- It is possible to buy a book written by the Antlr's author. I did not want to buy the book because I'm not planning to use Antlr in the future. But then I discovered that the online documentation is partial and often referring to the old 2.7.2 version.
- The produced java classes can have a method to get the AST tree, but as far as I understood the tree cannot be used for an interpreter, but only to check the result of the statement parsing.
- To build an interpreter is not the only purpose for using a parser:
Antlr is used for many other things, for example to compile, which
means convert expressions from a grammar to another one. Consider this to avoid to get confused reading the documentation.
- You can add java code directly in the grammar. With this code you can build the interpreter structures directly in the generated java code.
- Be very careful about the case of the initial letter of the rule names. Upper case: lexer rule; Lower case : parser rule. It looks simple, but if only the initial letter of one rule name is wrong nothing works as it should.
- The lexer is used to parse single words (identifier, strings, numbers). The parser is used to parse phrases.
- Spaces are handled automatically by the parser.
- In the java code that you add to the grammar you can set the package of the generated classes.
- AntlrWorks generates two types of java classes: the ones to use in your application and the ones that it uses to debug. They are saved in the same place with the same names. The debug classes don't work in your application, so remember to generate the application classes after a debug session.
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