Nugroho's blog.

Tuesday, May 24, 2016

Saturday, May 21, 2016

Thursday, May 12, 2016

Bounce Over Spherical Surface

#code

from visual import *
from random import uniform


display(center=(0,2,0),background=(1,1,1), autoscale=False, range=7.5,        
        width=600, height=600,  forward=(-.4,-.3,-1)) #arah kamera

distant_light(direction=(1,1,1), color=color.red)

ball        = sphere(radius=2, color=color.red, opacity = .5)
r2          = ball.radius
silinder    = cylinder(radius=2, length=4, opacity=.3)
silinder.rotate(angle=pi/2, axis=(0,0,1),origin=(0,0,0))


bola        = sphere(color=color.green,radius=.2)
bola.y      = 3
bola.x      = uniform(-1,1)
bola.z      = uniform(-1,1)


v           = vector(0,2,0)
dt          = 1./8.
r           = bola.pos

def pantul():
    global r,v
    print v
    if mag(r)<r2:
        print mag(r)
        arah    = norm(r)
        dv      = dot(v,arah)
        v       -= dv*arah
        r       = (r2+.2)*arah
    
    

def proses():
    global r,v
    a   = vector(0,-1,0)
    v   += a*dt
    r   += v*dt

    bola.pos  = r

    pantul()

    

while 1:
    rate(11)
    proses()

Tuesday, May 10, 2016

N-Spring System

Using Visual Python

I like the result, :)

#code
from visual import *

n       = 13
display(center=(n/2,0,0),background=(1,1,1), autoscale=False, range=(7),        
        width=600, height=600,  forward=(-.4,-.3,-1)) #arah kamera

distant_light(direction=(1,1,1), color=color.orange)
dt      = 1./8.
dx      = []
k       = []
m       = []
l0      = []
l       = []
v       = []
x       = []
for i in arange(n):
    dx.append(.1)
    k.append(1.)
    m.append(1.)
    l0.append(1.)
    l.append(1.)
    v.append(0.)
    x.append(0.)
pegas   = []
kotak   = []

for i in arange(n):
    spring  = helix(pos=(0,0,0), axis=(5,0,0), radius=0.2, color=color.red, length=1.)
    pegas.append(spring)
    ko      =  box(pos=(0,0,0), width=.5, height=.5, length= .5, color= color.green)
    kotak.append(ko)

box(pos=(-1,.64,0), width=n, height=2, length= 2, color=color.black)
box(pos=(n/2.,-.36,0), width=n, height=.2, length= n, color=color.white,opacity=.9)

#usikan
l[0]        = 1.2 
l[n-1]      = .9
#posisi x
position    = 0
for i in arange(n):
    position    +=l[i]
    x[i]        = position
    kotak[i].x  = x[i]


def updatePegas():
    global l
    for i in arange(n):
        if i!=0:
            pegas[i].x  = x[i-1]
            l[i]        = x[i]-x[i-1]
        else:
            l[i]        = x[i]

        kotak[i].x      = x[i]
        pegas[i].length = l[i]
        
def proses():
    for i in arange(n):
        dx[i]   = l[i]-l0[i]
        f0      = -k[i]*dx[i]
        if i<n-1:
            dx[i+1] = l[i+1]-l0[i+1]
            f1      = -k[i+1]*dx[i+1]
            a       = (f0-f1)/m[i]
        else:
            a       = f0/m[i]
        v[i]    += a*dt
        x[i]    += v[i]*dt
    updatePegas()
while 1:
    rate (19)
    proses()

Monday, May 9, 2016

Sunday, May 8, 2016

Akhirnya.

With Visual Python module

I couldn't use list for spring length since it'll trigger some error for helix object. It's very unfortunate because it would come handy as we expand the number of spring and mass.

Anyway, here's the code

#code
from visual import *
from random import uniform,random
from visual.controls import *

display(center=(1,0,0),background=(1,1,1), autoscale=False, range=(2,2,2),        
        width=600, height=600,  forward=(-.4,-.3,-1)) #arah kamera

distant_light(direction=(1,1,1), color=color.red)
n       = 2
dt      = 1./8.
pegas   = []
kotak   = []
box(pos=(-1,0,0), width=2, height=2, length= 2, color=color.black)
box(pos=(0,-.36,0), width=2, height=.2, length= 5, color=color.black,opacity=.3)
for i in arange(n):
    spring  = helix(pos=(0,0,0), axis=(5,0,0), radius=0.2, color=color.red, length=1.)
    pegas.append(spring)
    ko      = box(pos=(0,0,0), width=.5, height=.5, length= .5, color= color.green)
    kotak.append(ko)

k0      = 1.
k1      = 1.

m0      = 1.
m1      = 1.

l00     = 1.
l01     = 1.

l0      = 1.
l1      = 1.1

x0      = l0
x1      = l0+l1

v0      = 0.
v1      = 0.


y = 1.
print x1
def updatePegas():
    global x0,x1
    kotak[0].x      = x0
    pegas[0].length = l0
    
    kotak[1].x      = x1
    pegas[1].x      = l0
    pegas[1].length = l1

    

def proses():
    global l0,v0,x0,l1,v1,x1
    #untuk m0
    dx0     = l0-l00
    f0     = -k0*dx0
    dx1     = l1-l01
    f1     = -k1*dx1
    a0      = (f0-f1)/m0
    v0      += a0*dt
    x0      += v0*dt
    l0      = x0
    #untuk m1
    a1      = f1/m1
    v1      += a1*dt
    x1      += v1*dt
    l1      = x1-x0
    
    
    updatePegas()
    
while 1:
    rate (39)
    y   += .1
    proses()

Saturday, May 7, 2016

Tangkisan.

Banyak yang sibuk menangkis tuduhan dengan menyerang balik. Atau dengan menghabiskan waktu menjawab dan mengklarifikasi segala macam tuduhan.

Jarang ada yang membuktikan dengan tindakan bahwa tuduhan itu tak benar.

Lebih jarang lagi yang cuek, melanjutkan hidup, tanpa perlu membuktikan apapun.

Padahal yang terakhir membutuhkan energi yang lebih sedikit.

#Megatruh

Nugroho's blog.

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