Installation problems are relatively rare. They are usually caused by support components not being installed correctly, due to system-wide security problems.

The installer must be run as an administrator. However, being logged in as an administrator does not cause the installer to be run with administrator privileges. You must explicitly run it as an administrator.

To run the installer as an administrator, go to where InstallFac4V.exe has been downloaded (usually your Download directory), right click the installer and select “Run as Administrator.”

Check the dongle is attached correctly. If not working,check that the driver for the dongle is installed correctly. You can fix this by installing it manually using these steps:

The license file is supplied with a temporary activation as a courtesy to users, to allow them to use the application as soon as they download it. If you choose to install it at a later date you will simply need to permanently activate the license before you can use the software. (Note: once the temporary period has expired, most of the menu items will be inactive when you start the application; however, the help menu required to activate the license will still work.)

b) If you remove the FACSIMILE installation with Add/Remove Programs, the license file remains in the installation folder.

The solution is to save a license file in the FACSIMILE installation folder (normally C:\Facsimile4).

You need to be sure to have saved it in the right folder - specifically the folder containing Facsimile42.exe. 

The first thing to try is to remove and reinstall FACSIMILE (using add/remove programs). This will not remove the license file and, providing you install to the same folder, the license will still be valid. If you still have problems we would suspect the license file is corrupt so we will send a replacement file.

1. In Windows Explorer go to your FACSIMILE folder and right-click the file "Facsimile42.lf".  Select "Properties" and make sure the "Read only" and "hidden" boxes are unchecked.

2. Start FACSIMILE and go to menu item Help > Registration menu > Get Registration Details. Make a note of the Code Entry Number displayed (you may have to scroll down in the text box to see the CEN entry).

3. Close FACSIMILE and restart Windows.

4. Repeat step 2.

5. If the code entry number is the same in step 2 and 4 proceed to apply for a trigger code as normal. If not contact support for an alternative procedure.

The settings recommended for MCM are:

1. Open the Workspace Sizes tab again.
2. Type a label (such as MCM) in the text area towards the bottom of the page (labelled Stored Workspace Set).
3. Click [Save these settings as workspace set].
4. With future models loaded you will be able to select your label from the dropdown list and click [Load settings from workspace set].
5. Then click "Apply" to set the parameters.

There is no real random number generator in the FACSIMILE modelling language. We have a pseudo-random generator function called RANDOM but it will always produce the same sequence from a given seed. For your information, it is illustrated in the attached model. Calling RANDOM with a real argument >1.0 will seed the generator (only the integer part of the real is significant) calling with any number between 0 and 1.0 produces the next random number.

rndtest.fac

FACSIMILE VARIABLES are the only objects that are involved in the integration process and therefore the only objects that can have derivatives. You can’t get the derivative of a PARAMETER B because it hasn’t got one. That only applies if you are using parameter in the FACSIMILE sense, rather than the mathematical sense.

 

The derivative of a FACSIMILE VARIABLE is denoted by proceeding the name with a single quote mark. The derivative of A is ‘A. This notation can be used both to access the value of the derivative and to assign a value. The reaction A –k-> B can be written in block EQUATIONS using either chemical notation:

% k : A = B;

Or using derivative notation:

‘A= -k*A;

‘B=k*A;

You can use both types of notation in an EQUATIONS block.

 

The model files below, illustrate using the two types of notation and also accessing the value of a derivative:

You can only change the value of Variables (i.e. items involved in the integration process) in block EQUATIONS.

If you have issues where the model suddenly terminates, a common cause of this is users changing the value of a variable in a block other than equations, and this either causes the integrator to fail gracefully (with error saying it can’t continue), or to crash.

 

The FACSIMILE integrator uses a predictor/corrector method to perform the integration. Clearly a step change in any variable during integration process, would produce a discontinuity which would cause the integration process to fail.

If you need to do this you need to restart the integration process using ADD or RESTART. See Chapter 4 of the Technical Reference (techref.pdf).

In this case you need to check the log, as it will be incomplete.

An incomplete log doesn’t end with lines similar to this:

This is a problem with the integrator engine crashing. For reasons of efficiency (there are millions of arithmetic operations in even a simple simulation), the integrator has minimal error checking to shorten run times. This means that numerical errors in the problem will sometimes cause the integrator code to terminate with an exception.

By their nature, FACSIMILE problems tend to be ill-conditioned. Because the underlying process is solving a sparse matrix, some problems will run into numerical difficulties resulting in the integrator terminating due to underflow errors. The fact that the behaviour of your model is modified by changes in "Variable" or "Parameter" values, suggests that your model is on the edge of such a numerical failure.

However, by default, FACSIMILE uses the runtime from an older FORTRAN implementation, for backward compatibility reasons. There is some evidence that this runtime is not as robust with modern processors. We now recommend that the more modern runtime is used on the latest processors. Changing to the more modern integration engine may well solve your problem. "Setting the FACSIMILE Integration Engine.pdf" gives details of how to make this change.

The way to solve this is as follows:

FACSIMILE simply solves a system of differential equations.

If the results are not consistent or as expected, it means that your model is incorrect in some way.

The only solution to this is a careful analysis of your model and it’s values. It is sometimes easier to do this by breaking your model into small models, to test subsets of your equations are behaving as expected.

If you click the “Open Model” button, select your model then click “Open”, and you get an error message. A crucial clue to how to diagnose this is, does this happen with other models?

If you don’t have another model, try the simple model hello.fac at the end of this message.

If the error occurs with other models, then he fault is probably a corruption of the FACSIMILE software. The solution to this would normally be to reinstall the software. If that doesn’t work, and as we know the software was running correctly, you need to establish what has changed on your system to prevent the software running correctly. This is not a problem with the FACSIMILE software, and you will have to contact your IT department to fix the issue.

If the problem is just with your model it suggests that the model is corrupted in some way. Maybe this could be fixed by retrieving a previous copy from backup. 

You could also try this:

The way FACSIMILE works is as follows:

The user interface takes care of editing, initiating model runs and viewing results. The actual simulation is carried out by a separate executable, the FACSIMILE engine. The user interface hands control to the engine to carry out the simulation, and the interface resumes control when the process completes. The engine simply reads the plain text model file to carry out the simulation - it has no concept of previous versions, and if you have saved your edits to your model file that is what it runs. The engine also writes out the log file, overwriting any log from previous runs.

The most likely scenario which gives the impression of "running a previous model", is that mods to the model file have caused the integration engine to crash before it opens the log file, thus leaving the log from a previous successful run behind. You can check this by inspecting the date/time stamp on the log file, but the easiest way is to delete the log file before you start a run.

Other issues which may be causing you problems are:

The way FACSIMILE works is as follows:

The user interface takes care of editing, initiating model runs and viewing results. The actual simulation is carried out by a separate executable, the FACSIMILE engine. The user interface hands control to the engine to carry out the simulation, and the interface resumes control when the process completes. The engine simply reads the plain text model file to carry out the simulation - it has no concept of previous versions, and if you have saved your edits to your model file that is what it runs. The engine also writes out the log file, overwriting any log from previous runs.

The most likely scenario which gives the impression of "running a previous model", is that mods to the model file have caused the integration engine to crash before it opens the log file, thus leaving the log from a previous successful run behind. You can check this by inspecting the date/time stamp on the log file, but the easiest way is to delete the log file before you start a run.

Other issues which may be causing you problems are:

If you are trying to use FACSIMILE Function names as VARIABLES or PARAMETERS, then his will give an error in your log file.

A common misuse is the function "Abs".

You can find a list of FACSIMILE names in Appendix B of the User Guide.

If your model is accurate and the initial value is a good approximation, you should get the best fit for that parameter. If the value you get is not what you expected, either:

Trying to fit multiple parameters does not make sense numerically, and the fitting routines were not designed to do that. If you really want to fit more parameters you can manually edit the model file to include extra parameters. If you inspect the model you will see a line after the data block of the form:

(where aaa bbb ccc are parameter names).

You can add extra parameters to this list separated by spaces. Remember a line in FACSIMILE can not be greater than 72 characters long.

There is no guarantee that a solution can be computed and there is certainly no guarantee that a solution will be unique or relevant.

For example. You specify each of your reactants in a 6x6 array (to correspond to the cells in a 3x2 matrix).

So (for example):

(Note: FACSIMILE array indices start at zero so the 6 elements are numbered 0 to 5)

The pipe model "pipe.fac" describes how to construct a model which uses diffusion. 

where Df is the diffusion term. 

The FACSIMILE manuals are installed with the software in the FACSIMILE folder. The files are:

 They can be accessed directly, or from the help menu.

The easiest way to do this is to define the reactant as a parameter (rather than a VARIABLE). It’s value will then be unchanged.

This is illustrated by the simple model below, "static.fac". In this model the component A remains constant even though it is consumed in the first reaction and created in the second.

User reports log file contains message such as Names table full.

Error may refer to NPARS, NINTS, NCODE, NAMES, NTEXT , MATSZ, NCURV, NVARY , NOBSM, NPTTN.

The tab character (ASCII 9) is not part of the FACSIMILE character set.

Including this in a model can result in truncated lines or “character not found” type errors.

An easy way to detect this is open the model in Word, and click the: