Please write the c-code below in matlab.

#include<stdio.h> 
 int main() 
{
 const int MAX = 1000; 
char number[MAX+1]; 
int index;
 int j; 
for(index = 0; index <= MAX; index++) 
{ 
number[index]=1;
 } 
for(index = 2; index
 <= MAX; index++)
 { 
if(number[index]==1) 
{ 
for(j=2*index; j<=MAX; j=j+index) 
{ number[j]=0;
 if(index%2==0) 
number[j]=0; 
else 
if(index%3==0) 
number[j]=0; 
else 
if(index%5==0) 
number[j]=0;
 else 
if(index%7==0) 
number[j]=0; 
} 
} 
} 
printf("The following numbers are prime:\n");
 for(index=2; 
index<=MAX; index++) 
{ 
if(number[index]==1) 
printf("%d\n",index);
 } 
return 0; 
}

[Walter Roberson]

The code only checks factors 2, 3, 5, 7, and so produces incorrect answers for starting from 11^2 = 121.

A number of people have posted code to produce primes; why not use one of them?

Answer 1

[Athul Prakash]

Hey Attcharapan,

I presume that you're trying to do somethign similar to the Sieve of Erastosthenes alrogithm and find prime numbers in the given range. You may check out the following File Exchange submission implementing the same:https://www.mathworks.com/matlabcentral/fileexchange/73941-erathostenes

Please note that File Exchange submissions are shared by the MATLAB user community and are not official Mathworks products (they are not written or tested by Mathworks itself).