c calculating pi by throwing stones
c
PROGRAM stones
IMPLICIT none
c
c declarations
REAL*8 area, x, y, DRAND48
INTEGER i, max, pi, seed
c
c set parameters (number of stones, seed for generator)
max = 1000
seed = 11168
c
c open file, set initial value, seed generator
OPEN(6, FILE='pif.dat')
pi=0
call seed48(seed)
c
c execute
DO 10 i=1, max
x = DRAND48()*2-1
y = DRAND48()*2-1
IF ((x*x + y*y) .LT. 1) THEN
pi = pi+1
ENDIF
area = 4.0 * pi/REAL(i)
WRITE(6,*) i, area
10 CONTINUE
STOP
END
program main
include "mpif.h"
double precision PI25DT
parameter (PI25DT = 3.141592653589793238462643d0)
double precision mypi, pi, h, sum, x, f, a
integer n, myid, numprocs, i, ierr
c function to integrate
f(a) = 4.d0 / (1.d0 + a*a)
call MPI_INIT(ierr)
call MPI_COMM_RANK(MPI_COMM_WORLD, myid, ierr)
call MPI_COMM_SIZE(MPI_COMM_WORLD, numprocs, ierr)
10 if ( myid .eq. 0 ) then
print *, 'Enter the number of intervals: (0 quits) '
read(*,*) n
endif
c broadcast n
call MPI_BCAST(n,1,MPI_INTEGER,0,MPI_COMM_WORLD,ierr)
c check for quit signal
if ( n .le. 0 ) goto 30
c calculate the interval size
h = 1.0d0/n
sum = 0.0d0
do 20 i = myid+1, n, numprocs
x = h * (dble(i) - 0.5d0)
sum = sum + f(x)
20 continue
mypi = h * sum
c collect all the partial sums
call MPI_REDUCE(mypi,pi,1,MPI_DOUBLE_PRECISION,MPI_SUM,0,
& MPI_COMM_WORLD,ierr)
c node 0 prints the answer.
if (myid .eq. 0) then
print *, 'pi is ', pi, ' Error is', abs(pi - PI25DT)
endif
goto 10
30 call MPI_FINALIZE(ierr)
stop
end
var Pi=0, n=1, c=100000;
for (var i=0;i<=c;i++) {
Pi=Pi+(4/n)-(4/(n+2));
n=n+4;
}
function HitungPi()
{
var loop = document.getElementById("loop");
var c = parseInt(loop.value);
var f = parseFloat(loop.value);
var Pi=0, n=1;
try {
if (isNaN(c) || f != c ) {
throw("errInvalidNumber");
} else if (c<=0) {
throw("errNegativeNumber");
}
for (var i=0;i<=c;i++) {
Pi=Pi+(4/n)-(4/(n+2));
n=n+4;
}
document.getElementById("PiValue").innerHTML = Pi;
} catch (e) {
var msg = "Input Error: ";
if (e=="errInvalidNumber")
msg += "harus angka.";
else if (e=="errNegativeNumber")
msg += "Input harus positif.";
else
msg += e.message;
alert(msg);
}
}
<label for="loop">Jumlah iterasi:</label>
<input id="loop" type="number" value="100" />
<input type="button" onclick="HitungPi()" value="Hitung Pi" />
<div id="PiValue">Nilai Pi</div>
var canvas = document.getElementById('canvasexample'),
context = canvas.getContext('2d');
context.font = '38pt Arial';
context.fillStyle = 'green';
context.strokeStyle = 'red';
context.fillText('Hello Canvas',canvas.width/2-150,canvas.height/2+15);
context.strokeText('Hello Canvas',canvas.width/2-150,canvas.height/2+15);
My sky is high, blue, bright and silent.
Nugroho's (almost like junk) blog
By: Nugroho Adi Pramono
