FLUX
®
Exce Excell driv drivin ing g Flux Flux User User’s ’s Guid Guidee
February 2010 Copyright – February
FLUX 10
Table of Content
Table of Content 1. Guide Overview ................................................................ ............................................................................................................. .............................................1 1 2. The Excel Interface................................................................ Interface........................................................................................................ ........................................2 2 3. Using Excel to drive Flux .............................................................................................. ................................ ..............................................................4 4 4. Start the Solving Process ............................................................................................... ................................ ...............................................................6 6 5. The Function initVBAFlux ............................... ............... ................................ ................................ ............................... ............................ .............7 6. The Function StartVBAFlux Function StartVBAFlux ........................................................................................ 8 6.1. Initiali Initializing zing Flux ................................................................ ............................................................................................................ ............................................9 9 ...........................................................................................................12 ...........................................12 6.2. Geometry Input ................................................................ ..................................................................................................13 6.3. Modifying Modifying Radius Radius R ..................................................................................................13 ..................................................................................................................... .....................14 14 6.4. 6.4. Meshin Meshing g ................................................................................................ 6.5. Defining Defining Physics Physics ................................................................ ........................................................................................................15 ........................................15 6.6. Modifying the Current I ............................................................................................16 ............................................................................................16 6.7. 6.7. Solvin Solving g ................................................................................................ ....................................................................................................................... .......................17 17 6.8. Analysis Analysis of solved problem problem ........................................................................................18 ..............................................................................19 6.9. Closing Closing the Project, Project, Closing Flux ................................................................ ..............19 6.10. Analyzing Analyzing Results Results................................................................ .....................................................................................................20 .....................................20 7. The 7. The function closeVBAFlux closeVBAFlux .......................................................................................21 .......................21 8. Attachments ................................................................................................................22 ................................ ................22 8.1. Pyth Python on geom geomet etry ry inpu inputt : « geometry.py » ................................................................ ..................................................................23 8.2. Python Python meshing meshing : « meshing.py meshing.py »................................................................ ..............................................................................24 ..............24 8.3. Python Python physical properties properties : « buildphys.py »...........................................................25 8.4. Python Python solving solving : « solving.py » ................................................................ .................................................................................26 .................26 8.5. Python postprocessing : « postprocessing.py » ..........................................................27 8.6. VBA code code in the excel excel file ........................................................................................28 28
FLUX 10
1. Guide Overview
Goal
Example
Summary
The goal of this document is to explain and demonstrate how to drive Flux applications using Excel 2003. A basic example is included to support this goal.
A copper wire infinite in length carries a current. The radius of the wire is R, the magnitude of the current is I .
In our example, we will vary two parameters : The R value, radius of the wire (between 0 and 10 mm). The I value, magnitude of the current carried by the copper wire. The goal is: To measure the magnitude of the flux density B along a 25 mm long path extending from the center of the copper wire.
Note on Theory
The theoretical study of this example is easy to conduct using a close form solution. The flux density is computed in a point M at a distance r from the center of the copper wire. The next two equations give the close form solution for the flux density: On the left when the computation point is located inside the copper wire, On the right when the computation point is outside the copper wire
r R
Excel driving Flux
B
0 r I 2
R ²
r R
B
0 I 2
r
1
FLUX 10
2. The Excel Interface
Excel Interface
The screen shot below shows the Excel spreadsheet used as an interface.(2a)
2a
Parameter variables
Solve With Flux
The value contained in cell B5 and B6 can be changed: B5 : radius of the copper wire : R (mm) B6 : current carried by the wire : I (A)
When cell B5 and B6 are set, start Flux solving by selecting the menu item « SOLVE WITH FLUX ». Selecting « SOLVE WITH FLUX » runs a visual basic macro. The elements and actions executed by this macro are described in the next section.
2
Excel driving Flux
FLUX 10 Solving Process
Once the solving process is started, cell A13 to A18 are updated in real time giving a constant feedback on the activity of Flux and on the progression of the process. The coloring of the cells, yellow in our example, indicates the function active in the Flux process: Geometry input: cell A14. Meshing: cell A15. Physical properties: cell A16. Solving: cell A17. Post processing: cell A18.
Post processing
When the solving ends, the post processing updates the information in the table with the current results. In our example, the values contained in cells E5 to E30 are updated by the values computed during the post processing. These cells always show the results of the last solving process completed.. The plot associated to the table of results is automatically updated by Excel with the current results.
Excel driving Flux
3
Flux10
3. Using Excel to drive Flux
Introduction
Excel supports the development of VBA (Visual Basic for Applications) based macros. Flux supports Python based scripting, single commands or files. To drive Flux with Excel, python scripting of Flux, single commands or files, will be executed from VBA based macros in Excel. For the process to work correctly, the VBA macro from Excel must be able to locate the associated python scripting files. We will adopt a naming convention and chose a location for the files. This next section presents the strategy for driving Flux from Excel. It describes the chosen location for all the necessary scripting files.
Location of the files
The VBA macro file and scripting files must be stored as follows:
The main directory EXCEL_FLUX (any name not including extended characters.* Holds the Excel file “EXCEL_FLUX.xls” (any name not including extended characters) of our spreadsheet and the directory “w” (set name). The directory “w” is where all the python scripting files needed for the execution our processes are stored. The current example is developed using 5 different python files, all called by the Excel VBA macro. The name of the python file can be any name not including extended characters. *Note: when using FLUX, paths leading to the file being executed may not contain extended character, and cannot contain any spaces. This restriction stands when using Excel to drive Flux (see: Flux Users Guide vol. 1, sec4.1.1. pg.76).
4
Excel driving Flux
FLUX 10
Driving Flux
Steps followed when driving Flux from Excel, in the current example:
From Excel
Description of the Steps
In our example, selecting the menu item “SOLVE WITH FLUX” starts a macro. The following ten steps are then executed: 1. Initialize Flux, open connection to Flux, 2. Input problem’s geometry, 3. Read back value in cell B5 to modify value of R in geometry, 4. Mesh domain 5. Define physical properties for the problem, domain and regions, 6. Read back value in cell B6 to modify value of I, 7. Solve problem, 8. Compute results, 9. Close project file, close Flux, import result into Excel, 10. Process results in Excel and display variation curves.
Excel driving Flux
5
Flux10
4. Start the Solving Process
VBA code
Selecting the menu item “SOLVE WITH FLUX” starts the following VBA macro Code of the macro :
Filling the Cells
The first steps accomplished by the macro associated to the menu item “SOLVE WITH FLUX” are: - Color cell A13 yellow. - Color cells A14 à A18 white.
initVBAFlux
Once the cells are colored, the macro starts the function initVBAFlux. initVBAFlux sets the environment variables and loads the required “dll”. The environment variables are needed for the programs to find all necessary files and code.
StartVBAFlux
The next function to run enables the driving of Flux from an Excel spreadsheet. StartVBAFlux will also execute all of the steps described in the previous sections.
closeVBAFlux
The final function, closeVBAFlux ,will close Flux freeing the memory and unloading all of the “dll” called for during initialization.
6
Excel driving Flux
FLUX 10
5. The function initVBAFlux
Introduction
The function initVBAFlux initializes all the environment variable necessary for Flux to run. It also loads all of the “dll” needed for the running of the application
VBA Code
The next section details the code included in initVBA:
Location of Flux
The first step is to locate the directory where Flux was installed. This is done searching in the HKEY_LOCAL_MACHINE section of the registry for the location where the executable of the active version of Flux was installed. At the time of updating this document, the current version is 10.3. To proceed, we set the location where the address of the program we are looking for is located (key_name), and the name of the value we are trying to recover. The value we are looking for is Flux_10.3 (subkey_name) located in the directory SOFTWARE/Cedrat/INSTALLPATH (key_name) of the HKEY_LOCAL_MACHINE section of the register. The function GetRegKeyValue returns into the variable initVBAFlux the location where the active version of Flux is installed. *Reminder: The registry can be accessed from the command “regedit”. Type regedit in the run command of Windows.
Loading the dll
Once the location of the program is known, the “dll” needed to drive Flux from Excel are loaded. In our example, we load “resiflux.dll” and “flux_mp.dll”.
Excel driving Flux
7
Flux10
6. The function StartVBAFlux
Introduction
When the f unction InitVBAFlux is completed, the f unction StartVBAFlux starts. This function runs the Python files and commands developed to drive Flux from an Excel Spreadsheet
VBA Code
The code describing this function is too long to be shown as a whole. It will be explained in segments in the following sections. The sections will be: -
8
6.1. Initializing Flux 6.2. Entering problem’s geometry 6.3. Modifying radius R 6.4. Meshing 6.5. Setting physical properties 6.6. Modifying current I 6.7. Solving 6.8. Analyzing solved problem 6.9. Closing files, closing Flux 6.10. Analyzing results
Excel driving Flux
FLUX 10 6.1. Initializing Flux
Introduction
After completing the first function and setting InitVBAFlux, other initialization functions are required to insure a proper performance to pilot Flux This section spells out the necessary steps to take before running the python files. The first py. file described is the file pertaining to the geometry input, “geometry.py”.
Path to the Project
The project files will be created in the directory “w” where all of the Python scripting files used to create the new project are stored. Note that the directory “w” is located in the same directory as the Excel spreadsheet used to drive Flux. The first step is to set variable holding the location where the project will be saved. The following instructions set the path to the project being created:
Saving Excel File
The second step saves the Excel spreadsheet being used. Saving the file is required to register the modification performed on cells B5 and B6. The following instructions save the Excel spreadsheet:
Decimal Separator
The decimal separator used by Excel (and the M icrosoft programs more generally) depends on the native language support f unctions and the set language for Windows. The French speaking users have selected “,” as decimal separator, the English speaking users selected “.” as the decimal separator. To make the application usable by everyone, we must identify the type of decimal separator used by the person running the Excel spreadsheet. The following code identifies the separator used:
Excel driving Flux
9
Flux10 License Initialization
The third step sets and initializes the Flux license server (serverUid). This action requires loading a specific file and choosing a working mode for the license. The following code sets and initializes the license s erver:
The file used to set the license server is “multiphys.wfg”. The release mode (RELEASEMODE) is used for initialization.
Setting up Memory Requirements
This step sets up and reserves the memory necessary to run the application. It also sets the language used for the program, The following instructions set the memory and language:
In our current example, we will use a numerical memory of 600 MB (NUMERICAL_MEMORY_LABEL). The English language is set by default (LANGUAGE_LABEL).
10
Excel driving Flux
FLUX 10 Connection to License Server
The last step of the initialization is the connection to the license server. The following code connects to the local license server of Flux:
Note that the user must choose the version of Flux she/he wants to run. Four choices are available with version 10.3: Choice
FLUX2D_10.3_32 FLUX2D_10.3_64 FLUX3D_10.3_32 FLUX3D_10.3_64
Description 2D problem solved on a 32 bit computer 2D problem solved on a 64 bit computer 3D problem solved on a 32 bit computer 3D problem solved on a 64 bit computer
The user selects the location where the project will be created. In the current example, the project will be created at the location contained in the character string “Path”. This will be in the directory “w” located in the same level in the directory tree than the Excel spreadsheet.
Excel driving Flux
11
Flux10
6.2. Geometry Input
Introduction
The geometry is created from a python file run from the VBA code associated to the Excel spreadsheet.
VBA Code
The following code creates the geometry by running the Python script file geometry.py:
Filling Cell A14
Before the script “geometry.py” starts, the cell A14 is colored yellow. This indicates to the user that the geometry input is running.
Python Code
The detail of the code for the python script file “geometry.py” is in the attachment section of this document. This code includes : Creating a new project in Flux, Defining a geometric parameter R with a default value of 0.5 mm, Entering points in the domain, Entering lines connecting the points, Building faces, Saving project as: “testcase_ini.FLU”.
12
Excel driving Flux
FLUX 10
6.3. Modifying Radius R
Introduction
The radius R was entered as a geometric parameter. This geometric parameter is modified through a python command run from the VBA code associated to the Excel spreadsheet.
Python Command
The following python command modifies the value of parameter R setting it to 1:
VBA Code
The following code builds and calls the python command modifying the parameter R:
VBA Code
The code creates a character string “Test” set with the python command to run. Note that the value in cell B5 is read and converted in character string. In this character string, the function Replace() replaces “,” (decimal mark in French) by authorizing “.” as the decimal separator used by Flux as the decimal point “.”. The next to last line in the code executes the python command contained in the character string “test”, modifying the value of the geometric parameter R.
Excel driving Flux
13
Flux10
6.4. Meshing
Introduction
The geometry is now modified and ready to be meshed. The Python script file “meshing.py” holds the instructions to perform the meshing.
VBA Code
The following VBA code handles the meshing:
Coloring Cells A14 and A15
Cell A14 is colored black and white and cell A15 is colored in yellow before the file “meshing.py” is called. These changes of color indicate the progression of the process in the Excel spreadsheet, from the completion of the “MAKE GEOMETRY” geometry to the start of the “MESHING”.
Python Code
The detail of the code in the python script file “meshing.py” is in the “Attachment” section of this document. This code includes: Defining the mesh weights, Assigning the mesh weights to the geometric points, Meshing the faces, Saving the file as: « meshed_geom.FLU ».
14
Excel driving Flux
FLUX 10
6.5. Defining Physics
Introduction
The geometry being meshed, the Python script file “buildphys.py” is run to define the physics of the problem.
VBA Code
The following VBA code handles the physics:
Coloring Cells A15 and A16
Cell A15 is colored black and white and cell A16 is colored in yellow before the file “buildphysics.py” is called. These changes of color indicate the progression of the process in the Excel spreadsheet, from the completion of the “MESHING” to the start of the “BUILD PHYSICS ” process.
Python Code
The detail of the code in the python script file “buildphys.py” is in the attachment section of this document. This code includes: Setting the Application, Magnetostatics, and the solver being called, Solver3D, Creating an I/O parameter with a value 10 (Amp.) by default, Creating the surface regions Associating surface regions to geometric, Saving file as: « physbuilt.FLU ».
Excel driving Flux
15
Flux10
6.6. Modifying the Current I
Introduction
The value of the current I is stored in an I/O parameter. The value of this parameter is modified through a python command run from the VBA code associated to the Excel spreadsheet.
Python Command
The following python command modifies the value of parameter I setting it to 5:
VBA Code
The following code builds and calls the python command modifying the parameter I:
VBA Code
The code creates a character string “Test” set with the python command to run. Note that the value in cell B6 is read and converted in character string. In this character string, the function Replace() replaces “,” (decimal mark in French) by “.” as the decimal separator used by Flux is the decimal point “.”. The next to last line in the code executes the python command contained in the character string “test”, modifying the value of the I/O parameter I.
16
Excel driving Flux
FLUX 10
6.7. Solving
Introduction
The physics being completed, the Python script file “solving.py” is run to solve the problem. The problem is solved for the value of the radius R in stored in cell B5 and the value of the current I stored in cell B6.
VBA Code
The following VBA code handles the solving:
Coloring Cells A16 and A17
Cell A16 is colored black and white and cell A17 is colored in yellow before the file “solving.py” is called. These color changes indicate the progression of the process in the Excel spreadsheet, transitioning from the completion of the “BUILD PHYSICS ” to the start of the “SOLVING” process.
Python Code
The detail of the code in the python script file “solving.py” is in the “Attachment” section of this document. This code includes: Solving of the problem for the set values of the parameters R and I, Saving solved problem file as: « solved.FLU ».
Excel driving Flux
17
Flux10
6.8. Analysis of solved problem
Introduction
The solving being completed, the Python script file “postprocessing.py” is run to analyze the problem. The magnetic flux density is computed along a path 25 mm long, starting at the center of the copper wire.
VBA Code
The following VBA code handles the post processing:
Coloring Cells A17 and A18
Cell A17 is colored black and white and cell A18 is colored in yellow before the file “postprocessing.py” is called. These changes of color indicate the progression of the process in the Excel spreadsheet, from the completion of “SOLVING” to the start of the “POST PROCESSING”.
Python Code
The detail of the code in the python script file “postprocessing.py” is in the attachment section of this document. This code includes: Creating a path 25 mm long starting at the center of the copper wire with 25 subdivisions (1 subdivision every 1 mm), Plotting the curve of variation of the magnetic induction versus position along the existing path, Exporting the computed values into the file “Results.txt”, Saving the project as “postprocessed.FLU”.
18
Excel driving Flux
FLUX 10
6.9. Closing the Project, Closing Flux
Introduction
With postprocessing now completed, the Flux project and the program Flux can be closed.
VBA Code
The following VBA code handles the closing of fields and programs :
Coloring Cells A18 and A13
Cells A17 and A 13 are colored black and white. These changes of color indicate the progression of the process in the Excel spreadsheet, from the completion of the “POSTPROCESSING” to the end of processing.
Excel driving Flux
19
Flux10
6.10. Analyzing Results
Introduction
Flux having been closed, we can recover the results computed and stored when running “postprocessing.py”
VBA Code
This function recovers the values stored in the file “Results.txt” and distributes them into the cells E5 to E30 of the Excel spreadsheet. These results are displayed either with a comma or a point as the decimal separator. The following code spells the post processing functions:
Update of the result table
When the function is completed, the cells E5 to E30 are updated. The plot based on these values is also updated with the newly imported values.
20
Excel driving Flux
FLUX 10
7. The function closeVBAFlux
Introduction
The function closeVBAFlux closes the Flux environment and unloads all the “dll” loaded at the start of the macro.
VBA Code
The following code describes closeVBAFlux:
Excel driving Flux
21
Flux10
8. Attachments
Introduction
This section holds all of the scripts and macros used to drive Flux from Excel in our example.
Scripts and Macros developed
All of the script and macro files are printed in the following subsections:
22
-
8.1. Python geometry input « geometry.py » 8.2. Python meshing « meshing.py » 8.3. Python physical properties « buildphys.py » 8.4. Python solving « solving.py » 8.5. Python postprocessing « postprocessing.py » 8.6. VBA code in the excel file
Excel driving Flux
FLUX 10
8.1. Python File for geometry input: « geometry.py »
Excel driving Flux
23
Flux10
8.2. Python File for meshing: « meshing.py »
24
Excel driving Flux
FLUX 10
8.3. Python File for physical properties: « buildphys.py »
Excel driving Flux
25
Flux10
8.4. Python file for solving: « solving.py »
26
Excel driving Flux
FLUX 10
8.5. Python File for post processing: « postprocessing.py »
Excel driving Flux
27
Flux10
8.6. VBA Code in the Excel File
buttonStartFlux_Click()
Private Sub buttonStartFlux_Click() Range("A13").Interior.ColorIndex = 6 Range("A14:A18").Interior.ColorIndex = 0 initVBAFlux StartVBAFlux closeVBAFlux End Sub
initVBAFlux()
Function initVBAFlux() Dim key_name As String Dim subkey_name As String key_name = "SOFTWARE \ Cedrat \ INSTALLPATH" subkey_name = "Flux_10.3" initVBAFlux = GetRegKeyValue(HKEY_LOCAL_MACHINE, key_name, subkey_name) lib1 = LoadLibrary(initVBAFlux + "\ dll \ rsiflux.dll") lib2 = LoadLibrary(initVBAFlux + "\ dll \ flux_mp.dll") End Function
closeVBAFlux()
Function closeVBAFlux() Dim ignore As Long ignore = FreeLibrary(lib1) ignore = FreeLibrary(lib2) closeVBAFlux = 0 End Function
28
Excel driving Flux
FLUX 10 StartVBAFlux()
Sub StartVBAFlux() Dim i As Long Dim row As Integer Dim lig As String Dim Test As String Dim interm As Double 'project path path = ActiveWorkbook.path + " \ w" ' save Excel file ActiveWorkbook.Save ' Decimal separator "." or "," DecimalSeparator = Application.International(xlDecimalSeparator) '############################################################################ ' INIT FLUX '############################################################################ installFlux = initVBAFlux herror = FMP_init(installFlux + " \ bin \ multiphys.wfg", RELEASEMODE) If herror <> 0 Then GoTo ERROR '############################################################################ ' MEMORY '############################################################################ nbArg = 1 herror = FMP_arg(NUMERICAL_MEMORY_LABEL, "600000000", nbArg, args) If herror <> 0 Then GoTo ERROR nbArg = nbArg + 1 herror = FMP_arg(LANGUAGE_LABEL, "2", nbArg, args) If herror <> 0 Then GoTo ERROR '############################################################################ ' CONNEXION TO FLUX '############################################################################ herror = FMP_startLocaleServer("FLUX2D_10.3_32", path, args, nbArg, serverUid) If herror <> 0 Then GoTo ERROR
Excel driving Flux
29
Flux10
'############################################################################ ' GEOMETRY '############################################################################ Range("A14").Interior.ColorIndex = 6 herror = FMP_executeJythonCommand(serverUid, "executeBatchSpy('geometry.py')") If herror <> 0 Then GoTo ERROR '############################################################################ ' MODIFY RADIUS OF THE WIRE: R (mm) '############################################################################ Test = "ParameterGeom['R'].expression=" + "'" + Replace(CStr(Range("B5")), ",", ".") + "'" herror = FMP_executeJythonCommand(serverUid, Test) If herror <> 0 Then GoTo ERROR '############################################################################ ' MESHING '############################################################################ Range("A14").Interior.ColorIndex = 0 Range("A15").Interior.ColorIndex = 6 herror = FMP_executeJythonCommand(serverUid, "executeBatchSpy('meshing.py')") If herror <> 0 Then GoTo ERROR '############################################################################ ' BUILD PHYSICS '############################################################################ Range("A15").Interior.ColorIndex = 0 Range("A16").Interior.ColorIndex = 6 herror = FMP_executeJythonCommand(serverUid, "executeBatchSpy('buildphys.py')") If herror <> 0 Then GoTo ERROR '############################################################################ ' MODIFY CURRENT SUPPLIED THE WIRE: I (A) '############################################################################ Test = "VariationParameter['I'].formula=" + "'" + Replace(CStr(Range("B6")), ",", ".") + "'" herror = FMP_executeJythonCommand(serverUid, Test) If herror <> 0 Then GoTo ERROR
30
Excel driving Flux
FLUX 10
'############################################################################ ' SOLVE THE PROBLEM '############################################################################ Range("A16").Interior.ColorIndex = 0 Range("A17").Interior.ColorIndex = 6 herror = FMP_executeJythonCommand(serverUid, "executeBatchSpy('solving.py')") If herror <> 0 Then GoTo ERROR '############################################################################ ' POSTPROCESSING '############################################################################ Range("A17").Interior.ColorIndex = 0 Range("A18").Interior.ColorIndex = 6 herror = FMP_executeJythonCommand(serverUid, "executeBatchSpy('postprocessing.py')") If herror <> 0 Then GoTo ERROR '############################################################################ ' CLOSE PROJECT '############################################################################ Range("A18").Interior.ColorIndex = 0 Range("A13").Interior.ColorIndex = 0 herror = FMP_executeJythonCommand(serverUid, "closeProject()") If herror <> 0 Then GoTo ERROR '############################################################################ ' CLOSE FLUX '############################################################################ herror = FMP_stopServer(serverUid) If herror <> 0 Then GoTo ERROR '############################################################################ ' SHOW THE RESULTS '############################################################################ numFile = FreeFile Open path + " \ Result.txt" For Input As #numFile i=1
Excel driving Flux
31
