Re: a mathlink question

*To*: mathgroup at smc.vnet.net*Subject*: [mg89633] Re: [mg89620] a mathlink question*From*: "J. McKenzie Alexander" <jalex at lse.ac.uk>*Date*: Mon, 16 Jun 2008 06:37:28 -0400 (EDT)*References*: <200806151013.GAA12268@smc.vnet.net>

Does it have to be a C-program? If not, you can do this via J/Link in the following way. First, compile the following class: public class MemorySum { double total; public MemorySum() { total=0.0; } public double AddToPreviousSum(double x) { total += x; return total; } } Once you've compiled that and saved the class inside a jar file, create an instance of the class in Mathematica as follows: Needs["JLink`"]; InstallJava[]; AddToClassPath["Path/To/JarFile/filename.jar"]; object=JavaNew["MemorySum"] You then call the function as follows: In[29]:= object@AddToPreviousSum[10] object@AddToPreviousSum[10] object@AddToPreviousSum[10] object@AddToPreviousSum[10] object@AddToPreviousSum[10] Out[29]= 10. Out[30]= 20. Out[31]= 30. Out[32]= 40. Out[33]= 50. The J/Link documentation has more details regarding persistence of Java objects. Jason -- Dr J. McKenzie Alexander Department of Philosophy, Logic and Scientific Method London School of Economics and Political Science Houghton Street, London WC2A 2AE On 15 Jun 2008, at 11:13, GS wrote: > I would like to call a C-program from Mathematica. All the examples in > the MathLink tutorials (like AddTwo[i,j]) work like this: they are > called from Mathematica, are executed, send the result to Mathematica > and exit. > > I would like a C-program to not exit after the execution, and keep the > memory of the previous inputs. Say, I want an external C-program, to > be called as AddToPreviousSum[x]. When it is first called, it returns > x. When it is called the second time AddToPreviousSum[y], it returns x > +y. When it is called the third time AddToPreviousSum[z], it returns x > +y+z, and so on. > > How do I implement this in C using MathLink? > > Thanks. > GS. > Please access the attached hyperlink for an important electronic communications disclaimer: http://www.lse.ac.uk/collections/secretariat/legal/disclaimer.htm

**References**:**a mathlink question***From:*GS <vokaputs@gmail.com>