7 Replies Latest reply: Mar 3, 2011 10:28 AM by DavidShaw RSS

    MathCAD 11

    DavidShaw Copper

      There is one characteristic of MathCAD 11 that I have made use of when writing my own C code functions.

      The default parameter passing requires that the pointers to all the inputs be constant (const).

      However, I was implementing an adaptive filter and I needed to see the resulting coefficients, so I called the routine as follows:

       

        LRESULT  Nlms(  COMPLEXARRAY * const Nlms,
                          COMPLEXARRAY * const H,
                          const COMPLEXARRAY * const X,
                          const COMPLEXARRAY * const Y,
                          const COMPLEXSCALAR * const Step,
                          const COMPLEXSCALAR * const Points
                          )

       

      Not only could I see the resulting updates to the coefficients, but I could repeatedly press F9 over the function and re-run the same data over and over to get better and better results, sometimes while gradually adjusting to smaller and smaller step sizes.  This worked because subsequent calls used the coefficients starting at with results of the previous call.

       

      Unfortunately, someone at MathSoft figured out that this door needed to be closed, and in subsequent versions of MatCAD such tricks no longer work.

       

      The technique I use now is to append the coefficients to the end of the output from the adaptive filter, strip them off into a new vector, and then call a new copy of the function with the new coefficient vector.  Not a very satisfactory technique as one can appreciate.

       

      I wonder if there is any equivalent game to my earlier technique that I can play to return to this idea in more recent versions?

       

      David Shaw

        • Re: MathCAD 11
          MikeArmstrong Diamond

          What version of Mathcad are you now running.

           

          A worksheet would be helpful to get a clear idea of what you are doing.

           

          Mike

            • Re: MathCAD 11
              DavidShaw Copper

              Hi Mike,

               

              I am running 14 at the moment, but I would really like to get back to 11.  However, I have had to semi-retire my old machine, and the new one is running Window7 and I have not succeeded in getting 11 installed properly on the new machine with activation issues etc.

               

              Many years ago, before PTC I made some enquiries through MathSoft about the problem when I got version 12 and some kind developer got back to me, but I was absolutely swamped at the time and just could not follow through properly.

               

              Here is the last correspondence I remember with source for the main function nlms(), plus a worksheet with an example of how the whole thing worked.

              Sorry, but the necessary DLL with this function internal has a bunch of other proprietary stuff in it, so I can't really post that.

               

              Appreciate any input.

              David Shaw

                • Re: MathCAD 11
                  MikeArmstrong Diamond

                  A lot of users have had problem with worksheets that worked in version 11 and not in the later releases. I'm afraid that's the way it is. I would suggest putting M11 back onto your 'semi-retired' machine.

                   

                  Mike

                    • Re: MathCAD 11
                      DavidShaw Copper

                      How well does MathCAD 11 work under Windows 7?

                      How do I go about get the necessary activation code to get MathCAD 11 working on my new Windows 7 machine?

                       

                      Thanks,

                      David Shaw

                        • Re: MathCAD 11
                          MikeArmstrong Diamond

                          How well does MathCAD 11 work under Windows 7?

                          I don't personally know. I have heard of issues, but people have found work around's as described above.

                          How do I go about get the necessary activation code to get MathCAD 11 working on my new Windows 7 machine?

                          I take it you have a copy of Mathcad 11? If so, you could contact the Mathcad license and Install team.

                           

                          mathcadlicensing@ptc.com.

                           

                          Mike

                          • Re: MathCAD 11
                            StuartBruff Platinum

                            David Shaw wrote:

                             

                            How well does MathCAD 11 work under Windows 7?

                            How do I go about get the necessary activation code to get MathCAD 11 working on my new Windows 7 machine?

                             

                            Thanks,

                            David Shaw

                            Dave,

                             

                            I'm running M11 under Windows 7 Ultimate (32-bit) without any problems (or none that I've noticed anyway).   And that's in parallel with both M14 and now M15/Prime.

                             

                            Stuart