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+--- Thread: Sob (/thread-18548.html)
Pages: 1 2
RE: Sob - tangdfx - 07-18-2022 03:21 PM
Hi， Tony
Is it link to the malfunction of tvm financail function on multi calc and harald classic board on model HP 37 HP 38E/C？
There are few people play financial model to find these unnormal phenomenon.
RE: Sob - teenix - 07-18-2022 10:19 PM
(07-18-2022 03:21 PM)tangdfx Wrote: Hi， Tony
Is it link to the malfunction of tvm financail function on multi calc and harald classic board on model HP 37 HP 38E/C？
There are few people play financial model to find these unnormal phenomenon.
Not sure what the tvm function is
cheers
Tony
RE: Sob - rprosperi - 07-19-2022 12:27 AM
(07-18-2022 10:19 PM)teenix Wrote: Not sure what the tvm function is
cheers
Tony
tvm = Time Value of Money, the core N, I, PV, PMT, FV function/feature set on all the finance machines. They were a bit inconsistent on the early 80/70 Classic machines and the 22, a bit better on the 27 but overall have not changed much at all since HP-92.
RE: Sob - tangdfx - 07-19-2022 12:31 AM
Hi，Tony
TVM is time value of money.
The basic solver of N i PV PMT FV.
The result is wrong when you do TVM calculation in Multi calc and Harald which they share the same code actually.
The wrong result is only within the model HP 37 HP 38E and HP38C.
It is OK within HP 70 HP 80 HP 22 HP 27 .
RE: Sob - teenix - 07-19-2022 01:21 AM
OK thanks.
I can look at it but I am hamstrung living where I am at the moment. Just about everything I have is packed up in boxes spread out over relatives different places, not sure for how long.
The source code is published in the MultiCalc download and should simulate ok in Microchip MBLAB v5.05 ok if anyone else wants a crack at solving it :-)
cheers
Tony
RE: TVM (was sob) - Mike T. - 07-19-2022 10:08 PM
(07-19-2022 12:31 AM)tangdfx Wrote: Hi，TonyCould you post an example showing how to reproduce the error ? Thanks
TVM is time value of money.
The basic solver of N i PV PMT FV.
The result is wrong when you do TVM calculation in Multi calc and Harald which they share the same code actually.
The wrong result is only within the model HP 37 HP 38E and HP38C.
It is OK within HP 70 HP 80 HP 22 HP 27 .
RE: Sob - tangdfx - 07-20-2022 02:56 AM
Hi， Mike
I give you an example:
For N=360，I=0.27 , PV=1020000 , FV=0, in end mode.
Solve PMT should be PMT=-4439.10. But the Model HP37 ,HP38E,HP 38C show result PMT=-235006353.4
This problem only happen in physical emulator Multi clac and Harald board.
Thank you.
RE: Sob - tangdfx - 07-20-2022 02:30 PM
Sorry everyone.
It is my mistake due to misleading by the overlay.
The overlay exchange the PMT and PV button.
This is the root cause.
But anyway. There is another bug in the hardware of Multi Calc and Harald board.
Every time when you choose the model HP38C it will show Pr error.
This bug cause the continue memory can not be used.
RE: Sob - teenix - 07-20-2022 07:53 PM
(07-20-2022 02:30 PM)tangdfx Wrote: Sorry everyone.
It is my mistake due to misleading by the overlay.
The overlay exchange the PMT and PV button.
This is the root cause.
My mistake too, new files uploaded, thanks for pointing that out.
cheers
Tony
RE: Sob - Mike T. - 07-20-2022 11:09 PM
(07-20-2022 02:56 AM)tangdfx Wrote: Hi， Mike
I give you an example:
For N=360，I=0.27 , PV=1020000 , FV=0, in end mode.
Solve PMT should be PMT=-4439.10. But the Model HP37 ,HP38E,HP 38C show result PMT=-235006353.4
This problem only happen in physical emulator Multi clac and Harald board.
Thank you.
Interesting, on my HP38C emulator I get a result of '-4,433.51' which agrees with the result I get on my real HP12C as well as my HP22 and HP12C emulators.
'Swapping' PV and PMT over (which appears to be the cause of the problem) on my real HP12C gives '-234,667,432.8'.
However, these results are not exactly the same as the answers you gave. What model were you using?