#Free42 programs import plus
I can understand it for financial applications, I guess, but even there it's hard to see what problem would be caused by having $2 plus 5 times 20 cents minus $3 come out less than one tenth of one trillionth of a cent wrong. I don't understand what the fuss is about. And even today, programming in C or FORTRAN or Java it's the same. I started computer programming on a Commodore PET, 28 years ago, and one of the first things I noticed were numerical quirks like that. I suppose it depends on what you're used to. 2 + 3 - you get 8.8818e-16 also, 1 enter 1e-13 + 1 - to get 9.9920e-14 both of these are really annoying. here are some things that increasingly bug me (and you). how nasty!īut more and more recently i am going away from binary back to bcd.
ok, so then after effectively converting to decimal, i can algorithmically treat each part (M and E) separately eg mod(mod(M,r) + mod(10^E,r), r). what then happens, is that digits below M in significance are regarded as zero, although they wouldn’t be zero if kept in binary (there is implied decimal garbage if multiplied). so anyway, what im doing is temporarily recasting X into a decimal form but i store M in my floating point representation even though it is actually an integer (that’s because ints arn’t big enough). some decimal systems work entirely like this (ie using a binary mantissa), but the problem is that you have to cope with denomalised numbers. this is another way to tackle bcd, ie to have a binary integer mantissa and a power of 10 exponent. what i did in the end, and this approach works with similar decimal problems, is to decimalise the number by re-representing binary X by M*10^E where M is a binary integer. i had real trouble fixing this in scicalc for the same binary reasons. for example 1e50 enter 9 mod, comes out at 3 instead of 1. this is a bug.Īlso, binary is hampering mod.
#Free42 programs import windows
can you supply the bmp resource files to build the windows version. Lastly, thanks for writing this calculator!
#Free42 programs import code
i can give you some c code for ridders if you like, but i just cribbed it from numerical algorithms in C. it was part an attempt to recreate the missing solve and integ features on the hp9gĪlso, i had a substantial improvement for solve by moving from the secant method to ridder’s method as described there. this code i developed by trying to reverse engineer the method used on the 15c and it performs about the same, I see you need a ln1(x) = ln(x+1), here’s one i wrote for scicalc,Īlso, i can suggest a better integ algorithm. I have an alternative implementation of the gamma function you might like, i did the same in my implementation of scicalc but more and more recently i am going away from binary back to bcd. i can well understand your use of ieee754 not least from a performance point of view. firstly, your wrestle with bcd vs binary is something ive been struggling with for some time. I have a few ideas that might help it to become even better.
i like the palm version, it works well, although the beep is a bit loud.
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