# What is the best function to find prime numbers

(ahmed_seh) #1

assalmualikum guys

is there any function or code to find prime numbers??

i know that its hard to find them but i have to do it??

could u plz help me with that

(عبد العزيز غالب) #2

can be done simply using this code

[CENTER]p = primes(n)

[/center]

(ahmed_seh) #3

thank u very much dear friend

second part now

how can i choose randomly 2 large numbers from result of function primes???

i want to choose 2 numbers randomly and they must be large and not equal also,could u plz help me with that

i apperciate all ur help

my best wishes and regards

(عبد العزيز غالب) #4

we can design a function for that but there might be direct method for doing so !! any way i will try my best !!!

(عبد العزيز غالب) #5

alsalmu aleekum

this is a function can do the task and i do believe there is a single command line for these stuff

but this is from the programming prospective

``````
[SIZE=2][FONT=Courier New][SIZE=2][FONT=Courier New]clear[/font][/size]

[SIZE=2][FONT=Courier New]n= input([/font][/size][/font][/size][FONT=Courier New][SIZE=2][COLOR=#a020f0][FONT=Courier New][SIZE=2][COLOR=#a020f0][FONT=Courier New][SIZE=2][COLOR=#a020f0]'Enter the highest number: '[/color][/size][/font][/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2])[/size][/font]
[SIZE=2][FONT=Courier New]c=primes(n)[/font][/size]
[SIZE=2][FONT=Courier New]y=[0 0];[/font][/size]
[SIZE=2][FONT=Courier New]j=1;[/font][/size]

[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]while[/color][/size][/font][/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2][COLOR=#000000] (y(1)== 0) || (y(2)==0)[/color][/size][/font]
[SIZE=2][FONT=Courier New]x=uint32(10*n*rand(1));[/font][/size]
[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]for[/color][/size][/font][/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2][COLOR=#000000] i=length(c):-1:1[/color][/size][/font]
[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]if[/color][/size][/font][/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] (c(i)==x)[/size][/font]
[SIZE=2][FONT=Courier New]y(j)=x;[/font][/size]
[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]if[/color][/size][/font][/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2](y(2)==y(1))[/size][/font]
[SIZE=2][FONT=Courier New]y(2)=0;[/font][/size]
[SIZE=2][FONT=Courier New]j=j-1;[/font][/size]
[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]end[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]j=j+1;[/size][/font]
[/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]else[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]end[/color][/size][/font]
[/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]end[/color][/size][/font]
[SIZE=2][FONT=Courier New][COLOR=#0000ff]end[/color][/font][/size]
[/color][/size][/font][/color][/size][/font][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]y[/size][/font]
[/size][/font]
``````

i know it looks wierd but i would tell you believe it or not it is logically and algorithmatically correct
it is just the yemeni traditional way of thinking

buena suerte

(عبد العزيز غالب) #6

[CENTER]this is another code which is much much easier and take less execuation time

``````clear

n= input('Enter the highest number: ')
c=primes(n)
y=[0 0];
for i=1:2
x=uint32(length(c)*rand(1));
y(i)=c(x);
end
y

``````

[/center]

(المهندس سعود) #7

شوف الامر
out = randseed(state,m,n,rmin,rmax)

(المهندس سعود) #8

see help

(ahmed_seh) #9

thank u very much guys, now it works perfect

u r really very helpful and i apperciate ur response and im very happy 2 be one of ur friends in this forum

my best wishes and regards