How WOULD I create an "IF" syntax that if I had a number and DIVIDED it by another number my batch file would do [glb]one[/glb] thing if the result:

WAS a WHOLE number NOT equal to 1

and [glb]another[/glb] output if the result:

WAS NOT a WHOLE number NOT equal to 1

for example

5/2= Not Whole
6/2= 3 - Whole
7/7= 1 - Have same return as Not Whole

I am writing a batch file to generate prime numbers
Please help me
I will refine the number througr steps in division and eventually ECHO it back if it [glb]IS[/glb] prime

Thanks For Anything You Might Have
Sigma
Batch language can only do integer arithmetic in W2K or XP, but there is no functionality for floating point division. You either need to use one of many programming languages or one of many scripting languages availabe to Windows.

Get back to us if you need further ASSISTANCE. So is there any way to do division at [glb]ALL[/glb]?

for ex.)

if 25 divided by 5 == 5 (goto start)

Thanks for any help
SigmaYou can do some math with set /a

set /a 25/5

But it isn´t working if it is not an integer.

uliIT WORKED
I finally got mt batch file to echo [glb]ONLY PRIME NUMBERS[/glb]

Dont believe me?
Check the math...

25507
25511
25513
25517
25519
25523
25531
25537
25541
25547
25549
25553
25559
25561
25567
25573
25577
25579
25583
25589
25591
25597
25601
25603
25607
25609
25619
25621
25631
25633
25637
25639
25643
25649
25651
25657
25661
25663
25667
25673
25679
25681
25687
25691
25693
25699
25703
25709
25717
25721
25723
25727
25729
25733
25741
25747
25751
25757
25759
25763
25769
25771
25777
25783
25787
25789
25793
25799
25801
25807
25811
25813
25817
25819
25829
25831
25841
25843
25847
25849
25853
25859
25861
25867
25871
25873
25877
25883
25889
25891
25897
25901
25903
25909
25913
25919
25927
25931
25933
25937
25939
25943
25951
25957
25961
25967
25969
25973
25979
25981
25987
25993
25997
25999

Thanks for all the help
Sigma



I hate to burst your bubble, but the very first three prime numbers on your list are not prime. A noble try, but using the integer math available in batch language cannot solve this. There is no way to isolate the remainders.

A simple script, NEVER to be confused with a C program that can handle huge numbers, might go something like this:

Code: [Select]
For i = 1 to 1000000
primeflag = "y"
For j = 2 to i / 2
If i mod j = 0 Then
primeflag = "n"
Exit For
End If
Next
If primeflag = "y" Then WScript.Echo i & " is prime"
WScript.Sleep 100
Next


The code is only valid to 1 million and basically uses simple arithmetic, but it might give you some ideas. You can get a list of the first 10,000 primes from:

http://www.math.utah.edu/~alfeld/math/p10000.html

Well... perhaps my number sorter wasn't comprehensive enough... This was the process I used:

If CMD divides a number and it isn't whole it rounds DOWN 1. By comparing the output to what it should have been, I refined a number by dividing that number by and only by... [glb]2,3,5 and 7[/glb]
I thought that if a number WASN'T divisible by 2,3,5 or 7 that it was prime. Is this correct? Any suggestions?
Thanks for any help
Sigma

ps.) what would you do w/ that C program to run it?Prime numbers are those which have only themselves and one as divisors. The code above is a VB Script not a C program. To use it, CUT and paste the code into your editor (notepad will work fine), save it with vbs extension. Run in a cmd box:

cscript scriptname.vbs

The Sleep command will slow down processing, but will allow you to see the prime numbers as they go by. The script also gets progressively slower over time since many more divisions are necessary.

Note: I wrote this script down and dirty; if you find a bug, LET me know.