FFT Multiplication (HP-48G/GX/G+)

[Gerson W. Barbosa]

(02-15-2014 11:23 PM)Raymond Del Tondo Wrote:  Hi Gerson,

(02-15-2014 10:19 PM)Gerson W. Barbosa Wrote:  Something wrong?

Thanks for the hint. The binary in the attachment still has some debug info (like the stack view included). I updated the attachment by including a binary without debug info. Seems it was too late in the morning:-)

Please re-download the zip file.

Cheers

It's ok now, thanks! Now I get 22.25 seconds for two 64-element arrays, close to what you've reported. Just one more question: does your SysRPL do a List->Array conversion at the end? (I don't understand the code, but it appears to do that from the behavior of your previous compiled program. My latest HP-48GX version, as of yesterday, uses lists only once, to do the Hadamard multiplication. This has improved performance significantly. Would it do the same in SysRPL? (Assuming of course your SysRPL version corresponds to the older User-RPL version).

Cheers,

Gerson.

P.S.: Here is the updated table:

Code:


# elements     HP-71B     hp 49g      HP-48GX     hp 50g   48GX(SysRPL)
     16         24.11      10.42         9.96       5.57       5.44
     32         53.41      22.58        21.91      11.90       9.89
     64        116.74      47.86        47.64      25.16      22.22
    128        269.89     110.14       106.45      47.54      49.18
    256          --       255.87       254.00     104.42     110.11

The difference is most likely due to the final conversion to array, which wasn't being taken into account in the manual timing.