| Author | Message | ||
     Mongi Mansouri (mongim_pde) Member Username: mongim_pde Post Number: 13 Registered: 11-2003 |
Hi everyone... The library of special (non-analytic) functions in FPDE 2.22 (which is what I am using right now) is really limited. I have a problem right now getting the so-called Bessel functions of the first kind BESSI(0,x) and BESSI(1,x). Available in FPDE are BESSJ(order,x) and BESSY(order,x). I looked in the math handbook and could not see a clear realtionship between these. Does anyone know how to derive BESSI(0,x) and BESSI(1,x) from the presently available Bessel functions in FPDE? Thanks for your help. | ||
| Mongi Mansouri (mongim_pde) Member Username: mongim_pde Post Number: 14 Registered: 11-2003 |
This is a follow-up . I looked on the infinite sum forms of Bessel functions and observed that they are similar for the BESSJ(n,x) and BESSI(n,x) except for a multiplying factor (-1)^k that shows up in the former. So it may be an easy matter for FlexPDE developpers to add these functions... Feedback to previous question is greatly appreciated... Thank you. | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 94 Registered: 06-2003 |
BESSI(n,x) and BESSK(n,x) were implemented in version 3.00 back in 12/01. It appears that they never made it into the documentation, though. | ||
| Patricio A. Greco (pagreco) Member Username: pagreco Post Number: 15 Registered: 08-2003 |
I purchased the professional version 3 on 08/2003 , I need to pay any charge to upgrade to version 4? Thank you. | ||
| Mongi Mansouri (mongim_pde) Member Username: mongim_pde Post Number: 15 Registered: 11-2003 |
Dear Robert, I am still using version 2.22. It appears I may need to get an upgrade, because FPDE 2.22 still locks up after two days of computations. When this happens it will simply stop running but remains latched into memory and uses 99% of the CPU... I hope this can be fixed while I am using FPDE 2.22. | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 97 Registered: 06-2003 |
The latest maintenance release of version 2 was 2.22c1 in Dec, 2003. Is that the one you are using? (www.pdesolutions.com/download/versions/xfpde222c1win.exe) Did you send me the offending script so I can try it? | ||
| Mongi Mansouri (mongim_pde) Member Username: mongim_pde Post Number: 17 Registered: 11-2003 |
Yes. I am using the latest FPDE 2.22c1. However, I did not attempt to use BESSI() in my code because I assumed it was not included in this latest patch for FPDE 2.22. If it was included, then I will try it and let you know. Please accept my appology if I did not specify this detail. Thank you very much Robert. /Mongi M. | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 98 Registered: 06-2003 |
No, BESSI was added in version 3. I was referring to the hangup problem. Please send me the offending script. |