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I am just trying to use the command below
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..................
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....................Code:if (s[c]<1) {
naccept=naccept+1;
else {
nreject=nreject+1;
}
printf("naccept=%lf nreject=%lf\n",naccept, nreject);
.................
I am just trying to use if conditional statement to test values used using array
Thanx in advance
There's no matching closing braces before your else statement. What you need is
You should consider a better indentation style. I bet you would have seen the error that way.Code:if (s[c]<1)
{
naccept=naccept+1;
}
else
{
nreject=nreject+1;
}
I am not sure if this is your problem, but in the code you provided, you are missing the closing brace for your first if statement. Since you are only using one line after both your if and else, the braces are not necessary at all.
There is no format specifier "%lf" for printf.
If you're looking to print a float or double, use "%f".
I have this "}" closing bracket in my source code. Since i was coding using vim accessing the linux on windows platform, it ws hard for me copy the code and paste it so i wrote it and missed "}". And %lf works with my compiler.
And i am still having the problem. I get naccept =0 as well as nreject=0
Then it's a non-standard extension, so you should change it.Quote:
Originally Posted by curious
Then it's impossible to say why from that small snippet of code.Quote:
And i am still having the problem. I get naccept =0 as well as nreject=0
Code:for (c=0; c<NUM; c++)
{
r[c]=x[c]*x[c]+y[c]*y[c];
printf("r=%lf\n",r[c]);
s[c]=r[c]*r[c];
printf("s[c]=%lf\n",s[c]);
if (s[c]<1){
naccept++;
}
else {
nreject++;
}
}
As many people like to say:
Post the smallest possible compilable snippet of code that demonstrates the problem.
Code:
#include <stdlib.h>
#include <stdio.h>
#define NUM 100
#define IMAX 10
#define ISEED 777861
#define ISEED1 777862
#define RND() ((double)random()/(double)RAND_MAX)
main ()
{
int i, naccept=0, nreject=0, ntrial=0, c;
double x[NUM],s[NUM],r[NUM],pi;
srandom(ISEED);
naccept=0; nreject=0; ntrial=0;
for (i=0; i<NUM; i++)
{
x[i]=RND();
}
int j;
double y[NUM];
srandom(ISEED1);
for (j=0; j<NUM; j++)
{
y[j]=RND();
}
for (c=0; c<NUM; c++)
{
r[c]=x[c]*x[c]+y[c]*y[c];
printf("r=%lf\n",r[c]);
s[c]=r[c]*r[c];
printf("s[c]=%lf\n",s[c]);
if (s[c]<1){
naccept++;
}
else {
nreject++;
}
}
ntrial= naccept+nreject;
printf("naccept=%lf nreject=%lf ntrail=%lf\n",naccept,nreject,ntrial);
pi=4*(naccept/ntrial);
printf("pi=%.3lf\n",pi);
}
Implicit main is bad: http://cpwiki.sourceforge.net/Implicit_main
There is no identifier "%lf" for printf.
There is no function named srandom nor random.
(But there are srand and rand specifically.)
Would that be something to do with the floating point number, since s[c] is float, as i assume from the above snap of code. So what values do you get printed, when you print s[c]. Whats sort of values does that vector contain.
Some idea of values and input would help perhaps :-/
ssharish
You should perhaps get a quite lot linker error there when you compiler that code ????????????
Shoudn't that be rand and srand() ?????????? ;)
ssharish
It's basically values between 0.0000 to 1.70000 or something like that. my all other thing works expect that if condition statemen for s[c]. I don't why naccept and nreject aren't accumulating the values.
Small part of my result:
r=0.203552
s[c]=0.041433
r=1.747480
s[c]=3.053686
r=0.341290
s[c]=0.116479
r=1.269106
s[c]=1.610629
r=0.269674
s[c]=0.072724
naccept, nreject and ntrial are all integers and not floats and should be printed with %d.
try it with
ssharishCode:if( s[c] < 1.0 ) {
i have no problem getting random number and r and s but i didn't get naccept , nreject and ntrail.
The following code correct(er):
I suggest you update the code because are sure using some non-standard stuff.Code:#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#define NUM 100
#define IMAX 10
#define ISEED 777861
#define ISEED1 777862
#define RND() ((double)rand()/(double)RAND_MAX)
int main ()
{
int i, naccept=0, nreject=0, ntrial=0, c;
double x[NUM],s[NUM],r[NUM],pi;
srand( time(NULL) );
naccept=0; nreject=0; ntrial=0;
for (i=0; i<NUM; i++)
{
x[i]=RND();
}
int j;
double y[NUM];
//srandom(ISEED1);
for (j=0; j<NUM; j++)
{
y[j]=RND();
}
for (c=0; c<NUM; c++)
{
r[c]=x[c]*x[c]+y[c]*y[c];
printf("r=%f\n",r[c]);
s[c]=r[c]*r[c];
printf("s[c]=%f\n",s[c]);
if (s[c]<1.0){
naccept++;
}
else {
nreject++;
}
}
ntrial= naccept+nreject;
printf("naccept=%d nreject=%d ntrail=%d\n",naccept,nreject,ntrial);
pi=4.0*((double)naccept/(double)ntrial);
printf("pi=%.3f\n",pi);
}
It almost produces correct pi (ca 3.04x something I believe).
And only initialize the seed once.
hi Elysia , you are right it worked but it's not printing the value of pi
Thank you Elysia and ssharish
Sorry Elysia it worked
Thank you very much
This is my second program after learning c on my own. Can you please clarify those things . I am still confuse with rand and random stuff as well as seed.
Those stuff about %d and double.
Thanx,
When printing stuff with printf, you need to tell printf what type you're passing (it's not psychic).
%d tells printf the type is int. %f tells printf it's a double (or float).
And the random stuff works by initializing the seed once, and then calling rand. Rand will use the seed to generate random numbers. If you seed twice or more, you will see that you might actually get the same number as before (thus not really random).
%lf in C89 is undefined behavior. %lf in C99 is legal, but the l is ignored.