Login [Register]
Don't have an account? Register now to chat, post, use our tools, and much more.
This is an archived, read-only copy of the United-TI subforum , including posts and topic from May 2003 to April 2012. If you would like to discuss any of the topics in this forum, you can visit Cemetech's TI-BASIC subforum. Some of these topics may also be directly-linked to active Cemetech topics. If you are a Cemetech member with a linked United-TI account, you can link United-TI topics here with your current Cemetech topics.

This forum is locked: you cannot post, reply to, or edit topics. TI-Basic => TI-BASIC
Author Message
vic9317


Newbie


Joined: 16 Nov 2008
Posts: 26

Posted: 19 Feb 2011 11:55:26 pm    Post subject:

Aside from the traditional 1+int(log(abs(X))) trick, are there any other ways to check the length of a Real variable?

Here's the problem:
I want to truncate a number so that it will always have 6 digits. For example, 1.234567 would be truncated to 1.23457, while 12.34567 would be truncated to 12.3457, 123.4567 to 123.457, etc.

I'm able to use the round( command for this, such that I could do round(X,5-int(log(abs(X. This method seems to work with fair results, except for its major weakness, when X=0.

I'd like to avoid converting the number into a string and then using length( on it.

So... any ideas? Thanks in advance.
Back to top
montytyper


Newbie


Joined: 06 Nov 2010
Posts: 13

Posted: 20 Feb 2011 01:07:34 am    Post subject:

Round(x,5 isn't acceptable? I can't imagine why you would need a number to always be a specific length unless you were using it for some sort of string application. Also, why are strings unacceptable?
Back to top
vic9317


Newbie


Joined: 16 Nov 2008
Posts: 26

Posted: 20 Feb 2011 10:14:05 am    Post subject:

Qwerty.55 wrote:

Round(x,5 isn't acceptable? I can't imagine why you would need a number to always be a specific length unless you were using it for some sort of string application. Also, why are strings unacceptable?


I'm using the graph screen to display columns of fixed length, and each column can only fit about six digits' worth. Any more than six digits and the output of the data will overflow into the next column. (I originally had round(X,5), but once X = something like 10.12345, it becomes a problem.)

Converting the number to a string seems rather tedious for such a simple matter (not to mention it'll like slow down the code quite a bit, since I need to do this in a loop). Essentially, I'm using Text(R,C,round(X,5-int(log(abs(X, but of course, it won't work when X = 0.
Back to top
Deep Thought


Advanced Newbie


Joined: 09 Jun 2009
Posts: 59

Posted: 22 Feb 2011 09:24:48 am    Post subject:

Try Text(R,C,round(X,5-int(log(abs(Xnot(X.
Back to top
vic9317


Newbie


Joined: 16 Nov 2008
Posts: 26

Posted: 22 Feb 2011 11:36:23 am    Post subject:

Deep Thought wrote:

Try Text(R,C,round(X,5-int(log(abs(Xnot(X.


No dice; still would give Err:Domain when X = 0 (since 0*1=0) and, actually, when X ≠ 0 (since X*0=0).

However, Text(R,C,round(X,5-int(log(abs(X+not(X seems to work well. I've yet to try other cases other than X = 0 or X ≠ 0 (what other could there be?), but it looks good for now. Well, I suppose the only other exception is if X has an integer part with length of digits > 6, but I suppose I won't encounter too many of those.

Thanks for the suggestion!
Back to top
Sven.Thomas0


Active Member


Joined: 19 May 2009
Posts: 520

Posted: 22 Feb 2011 11:38:52 am    Post subject:

Deep Thought wrote:

Try Text(R,C,round(X,5-int(log(abs(Xnot(X.

You will want to do Text(R,C,round(X,5-int(log(abs(X+not(X so that X=0 will work.

EDIT: Ya ninja'd me Very Happy
I don't know if this could be useful, but to grab the first 6 digits of a number (regardless of where the decimal is) you can do int(Ans10^(5-int(log(Ans+not(Ans Pretty much, 19.66453 will make 196645 as does 196645300.7 or whatever. That just displays the first six digits of the number regardless of whether it is before or after the decimal Very Happy


Last edited by Guest on 22 Feb 2011 11:41:53 am; edited 1 time in total
Back to top
Deep Thought


Advanced Newbie


Joined: 09 Jun 2009
Posts: 59

Posted: 22 Feb 2011 03:50:33 pm    Post subject:

Whoops, fail'd there. .
Back to top
Display posts from previous:   
Register to Join the Conversation
Have your own thoughts to add to this or any other topic? Want to ask a question, offer a suggestion, share your own programs and projects, upload a file to the file archives, get help with calculator and computer programming, or simply chat with like-minded coders and tech and calculator enthusiasts via the site-wide AJAX SAX widget? Registration for a free Cemetech account only takes a minute.

» Go to Registration page
    »
» View previous topic :: View next topic  
Page 1 of 1 » All times are GMT - 5 Hours

 

Advertisement