Re: Request for Mathematica Programming help.

*To*: mathgroup at smc.vnet.net*Subject*: [mg36866] Re: [mg36825] Request for Mathematica Programming help.*From*: "Hermann Schmitt" <schmitther at netcologne.de>*Date*: Mon, 30 Sep 2002 03:03:08 -0400 (EDT)*References*: <an14fb$idu$1@smc.vnet.net> <200209280834.EAA24968@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I agree with Mr. Kuska, that the system Mr Nagesh describes is not userfriendly. But I think, the suggestions of Mr. Kuska do not make it more userfriendly, rather the opposite is true. Mr. Nagesh asks "Is any body here have expertise or information about the capability of Mathematica as a system simulation tool?" Mr. Kuska answers: "Since the most "system simulation tools" are simply solving a system of ordinary differntial equations it is simple to do this with NDSolve[]." My comment: That is: He sees the simulation system merely as a set of differential equations. The question of Mr. Nagesh: "My 4th Objective:- How can I program the check for correctness of the input values supplied by the package user ?" The answer of Mr. Kuska is: "And @@ (NumericQ /@ {aListOfAllYourNumericParameters})" My comment: This is a nice command and shows the knowledge of Mr.Kuska. But does Mr. Nagesh understand it and is it sufficient to check, if all inputs are numerical? Additionally I think, it is not userfriendly to see the input merely as a set of 200-250 numbers. My suggestion is, that JLink is used, a suggestion Mr. Kusk takes into consideration, too. But further I suggest, that classes are defined in Java, which represent the parts of the system. Constructors of the classes should build objects with default values. Graphical user interfaces should give the opportunity to change the data fields in the objects and check the input for correctness. The system should give the opportunity, to store the objects on harddisk (serialization). accessed directly. > Hi, > > > > > My name is Nagesh and pursuing research studies in Refrigeration. At > > present I am writing a Dynamic Refrigeration System Simulation Package. I > > am using Mathematica as a programming language for the same since last one > > year. I don't have any programming experience before this. I have following > > querries:- > > 1. Is any body here have expertise or information about the capability of > > Mathematica as a system simulation tool? > > Since the most "system simulation tools" are simply solving a system of > ordinary differntial equations it is simple to do this with NDSolve[]. > > > 2. Is is possible to program a user friendly interface for my system > > simulation package with Mathematica or I have to use some other software? > > Write a MathLink or J/Link frontend that launch the kernel. But you > should keep > in mind that the user interface is typical 80-90 % of your code. > If you just whant to solve some ode's it is probably easyer to > include one of the excelent ode-solvers from netlib in your C-code > than to call Mathematica to do that. As long as you dont wish to change > the ode's very often (than Mathematica is more flexible) you should > not use Mathematica. > > > 3. My refrigeration system simulation package is likely to have > > approximately 60 First order Differential equations. Is is possible to > > solve these in Mathematica ? > > Sure. > > If yes then can anybody here guide me about > > this further. > > Write down the equations and call NDSolve[]. > > > > > I am explaining below in short about the objectives I want to fulfill from > > coding out of my main input file > > > > 1. Example from Main Input File ( this will contain about 200-250 variables > > which will be entered by the user of this package) > > This sounds like a *very* userfiendly interface ;-) > > > > > Below is examples of two variables entered into this file, which will be > > used in other analysis files for further evaluation. > > > > 2. Example from other analysis file ( there will be about 20-25 other such > > component analysis files ) where the above mentioned variables from main > > input file will be used for further evaluations:- > > > > Below is one example from this file explaining how the variables from main > > input file will be used in other files. > > > > I hope that this short information will be useful for guiding me to solve > > the following problems that I am facing. I am facing follwing problems or > > objectives:- > > > > 1. My 1st Objective:- The user of this package must be able to change only > > the value of the variable in the main input file but he must not be able to > > change the name of the variable itself. For example he must be able to > > change the value of the variable " " but he must not be able to change the > > name of this variable itself. > > Here our problem is how to achieve or program it so that our objective will > > be fullfilled. > > Options with defaulf values ? or something like > > {aParam,bParam}={ODEParameter1,ODEParameter2} /. > userRules /. > {ODEParameter1->1,ODEParameter2->2} > > > > > 2. My 2nd Objective:- How I can program the main input file so that it will > > be user friendly in terms of its visuals and satisfying the constraint > > mentioned above in objective1. > > What is *userfiendly* in a file with 250 variables ??? > > > > > 3. My 3rd Objective:- How can I program the optional values for each > > variable in the main input file ? so that there will be always a value > > assigned to each variable listed in main input file whenever the user opens > > up this file. If user want to change the values of some variables then he > > can change them and run the simulation otherwise the simulation run will be > > done with optional values assigned to each variable in the input file. > > See above. > > > > > 4. My 4th Objective:- How can I program the check for correctness of the > > input values supplied by the package user ? > > And @@ (NumericQ /@ {aListOfAllYourNumericParameters}) > > > > Regards > Jens >

**References**:**Re: Request for Mathematica Programming help.***From:*Jens-Peer Kuska <kuska@informatik.uni-leipzig.de>