Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: How do you get Matlab to recognize 1000 digit numbers without
rounding?

Replies: 2   Last Post: Jan 7, 2013 10:31 AM

 Messages: [ Previous | Next ]
 Steven Lord Posts: 18,038 Registered: 12/7/04
Re: How do you get Matlab to recognize 1000 digit numbers without rounding?
Posted: Jan 7, 2013 10:31 AM

"Allen " <calderwoodra@vcu.edu> wrote in message
news:kcah58\$h8s\$1@newscl01ah.mathworks.com...
> I am working on project Euler and one of the problems asks you to find the
> largest product of 5 consecutive numbers in a given 1000 digit number. My
> question is how do I input this number without Matlab rounding?

No 1000-digit number can be represented as a finite double precision value
(unless the first 700ish digits are 0.) They will all overflow to Inf
or -Inf. Use Symbolic Math Toolbox instead.

a = sym('123456789012345678901234567890')

Note that the quotes are NECESSARY otherwise MATLAB will interpret your
string of 1000 digits as a double then convert the resulting Inf into a
symbolic object.

--
Steve Lord
slord@mathworks.com