"FOR" loop

20 次查看(过去 30 天)
Juan Alvarez
Juan Alvarez 2011-12-4
I have to find the prime numbers from that lead up to 100 and then use the 'for' function to multiply adjecent prime numbers: example:
first prime numbers
2 3 5 7
and i need the 'for' to do the following with the prime numbers
2*3 3*5 5*7 etc...HELP PLEASE
  1 个评论
Dinesh Kannan Natarajan
% to Generate prime number between the intervals
clear;
clc;
m=input('provide the required start point of prime number: ');
n=input('provide the required end point of prime number: ');
if n<=0
pr='Error';
disp('ERROR: Input argument must be a positive integer')
elseif round(n)~=n||round(m)~=m
pr='Error';
disp('ERROR: Input argument must be positive integer')
elseif n <= m
pr='Error';
disp('ERROR: end point must be greater than start point')
else
k=1;
for i=m:n
c=0;
for j=2:i-1
if rem(i,j)==0
c=1;
break
end
end
if c==0
pr(k)=i;
k=k+1;
end
end
end
pr

请先登录,再进行评论。

回答(4 个)

Junaid
Junaid 2011-12-4
let say your prime vector is P;
p=primes(100);
a = zeros(1,length(p)-1);
for i=1:length(p)-1
a(i) = p(i) * p(i+1);
end
a
though you can do it also without loop but you asked for a loop so it is loop solution.
  1 个评论
Juan Alvarez
Juan Alvarez 2011-12-4
im sorry but this did not help...
i am at here so far
k=primes(100)
then it list the primes but i cant figure out how to use the for loop at all

请先登录,再进行评论。


Junaid
Junaid 2011-12-4
p=primes(100);
A = zeros(1,length(p)-1);
for i=1:length(p)-1
A(i) = p(i) * p(i+1);
end
A
just copy and paste the code, answers is in vector (A) try this, do let us know if it is what you wanted to do.

Sean de Wolski
Sean de Wolski 2011-12-6
Loop sure seems like overkill
x = primes(100);
x1p1 = x(1:end-1).*x(2:end);

Andrei Bobrov
Andrei Bobrov 2011-12-4
a = 1:100;
yourprime = a(a - sum(rem(triu(bsxfun(@rdivide,a,a.')),1)>0)<=2);
out = prod(yourprime(bsxfun(@plus,1:numel(yourprime)-1,(0:1)')))
  1 个评论
Paulo Silva
Paulo Silva 2011-12-6
It takes a while for me to understand your code, nicely done

请先登录,再进行评论。

类别

Help CenterFile Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

尚未输入任何标签。

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by