forum.alglib.net

ALGLIB forum
It is currently Sat Apr 27, 2024 6:25 pm

View unanswered posts | View active topics


Board index » ALGLIB forum » ALGLIB-discuss

All times are UTC


Forum rules


1. This forum can be used for discussion of both ALGLIB-related and general numerical analysis questions
2. This forum is English-only - postings in other languages will be removed.



Post new topic Reply to topic  Page 1 of 1
  [ 5 posts ] 
  Print view Previous topic | Next topic 
Author Message
alglib
 Post subject: exponentialintegralei(x)
PostPosted: Fri Apr 15, 2011 2:14 pm 
Offline

Joined: Fri Apr 15, 2011 2:10 pm
Posts: 3
How great x can be?
I try Ei(100)=2.7e41. It is wrong. How ti calculate such great numbers7
Top
 Profile  
 
Doug Jenkins
 Post subject: Re: exponentialintegralei(x)
PostPosted: Sat Apr 16, 2011 12:08 am 
Offline

Joined: Sun May 16, 2010 11:42 pm
Posts: 63
Why do you think it is wrong?

Wolfram Alpha gives the same result.

_________________
Doug Jenkins
http://newtonexcelbach.wordpress.com/
Top
 Profile  
 
alglib
 Post subject: Re: exponentialintegralei(x)
PostPosted: Sat Apr 16, 2011 2:43 am 
Offline

Joined: Fri Apr 15, 2011 2:10 pm
Posts: 3
Sorry. Misunderstood.
Top
 Profile  
 
alglib
 Post subject: Re: exponentialintegralei(x)
PostPosted: Sat Apr 16, 2011 10:37 am 
Offline

Joined: Fri Apr 15, 2011 2:10 pm
Posts: 3
How can I calculate big values of thid functions?
x Ei(x,1)
1.670000e+002 1.768184e-075
1.680000e+002 6.466293e-076
1.690000e+002 2.364822e-076
1.700000e+002 8.648816e-077
1.710000e+002 -1.000000e+000
1.720000e+002 -1.000000e+000
1.730000e+002 -1.000000e+000
1.740000e+002 -1.000000e+000
Top
 Profile  
 
Doug Jenkins
 Post subject: Re: exponentialintegralei(x)
PostPosted: Sun Apr 17, 2011 11:04 pm 
Offline

Joined: Sun May 16, 2010 11:42 pm
Posts: 63
alglib wrote:
How can I calculate big values of thid functions?
x Ei(x,1)
1.670000e+002 1.768184e-075
1.680000e+002 6.466293e-076
1.690000e+002 2.364822e-076
1.700000e+002 8.648816e-077
1.710000e+002 -1.000000e+000
1.720000e+002 -1.000000e+000
1.730000e+002 -1.000000e+000
1.740000e+002 -1.000000e+000


170 seems to be the Alglib limit for this function. The equivalent function in the Xnumbers package goes up to 701.

_________________
Doug Jenkins
http://newtonexcelbach.wordpress.com/
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 1
  [ 5 posts ] 

Board index » ALGLIB forum » ALGLIB-discuss

All times are UTC


Who is online

Users browsing this forum: Bing [Bot] and 335 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group