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Calculator Community => TI Calculators => TI-BASIC => Topic started by: Raylin on November 28, 2010, 03:56:48 pm

Title: fPart and 1+int(abs(log(X
Post by: Raylin on November 28, 2010, 03:56:48 pm

Is there any way to test this (1+int(abs(log()))) nested inside of an fPart?

For example, this:

Code: [Select]

1+int(abs(log(fPart(Xdoesn't work.

This gets the # of digits in a number.

Title: Re: fPart and 1+int(abs(log(X
Post by: calcdude84se on November 28, 2010, 03:58:30 pm

I'm confused... What do you mean by your first line?
Also, for a positive integer, 1+int(log(X works.
What is X?

Title: Re: fPart and 1+int(abs(log(X
Post by: nemo on November 28, 2010, 03:58:51 pm

so you want to get the number of digits in the fractional part of a number, am i right?

Title: Re: fPart and 1+int(abs(log(X
Post by: Raylin on November 28, 2010, 04:00:58 pm

Quote from: nemo on November 28, 2010, 03:58:51 pm

so you want to get the number of digits in the fractional part of a number, am i right?

Yes.

Title: Re: fPart and 1+int(abs(log(X
Post by: calcdude84se on November 28, 2010, 04:03:41 pm

I don't think that's possible. You can tell how many leading 0's there are, but you can't tell how many significant figures there are.
log( won't distinguish much between .3333 and 1/3 x.x

Title: Re: fPart and 1+int(abs(log(X
Post by: nemo on November 28, 2010, 04:06:26 pm

i think you'd have to do the following, unless there's a neat math trick:

Code: [Select]

0->A
While fPart(X
10X->X
A+1->A
End

edit: and repeating decimals like 1/3 return 14 decimal places.

Title: Re: fPart and 1+int(abs(log(X
Post by: calcdude84se on November 28, 2010, 04:10:44 pm

Yeah, that's what I meant. No neat math trick, to my knowledge.
Your code should work fine, though. :)
Edit: I mean, we could use a nice recursive function...

Code: [Select]

f(x) = {0        x=int(x)}
       {1+f(x)  x<>int(x)}

Title: Re: fPart and 1+int(abs(log(X
Post by: FinaleTI on November 28, 2010, 04:12:25 pm

With Celtic III/DCS7, you could do:

Code: [Select]

length(det(1,X))-1-length(det(1,1+int(abs(log(X
;D

Title: Re: fPart and 1+int(abs(log(X
Post by: nemo on November 28, 2010, 04:13:30 pm

is that shorter than just using a loop though? it's probably faster granted

Title: Re: fPart and 1+int(abs(log(X
Post by: FinaleTI on November 28, 2010, 04:22:28 pm

That's probably larger than it needs to be.
How about:

Code: [Select]

length(det(1,X))-inString(det(1,X),".