2017年3月 – Python in the box

3月 22, 20173月 22, 2017

numpy/opencv 2次元FFT

離散フーリエ変換(DFT)の高速化版アルゴリズムFFTをnumpyで試す。

import numpy as np

#read imgs 
image = cv2.imread("input.png", 0)

#FFT by numpy
fimage = np.fft.fft2(image)

fimage = np.log(np.abs(fimage) + 1)

fimage = fimage / np.amax(fimage) * 255
cv2.imwrite("result.png", fimage)

import numpy as np

#read imgs

image = cv2.imread("input.png", 0)

#FFT by numpy

fimage = np.fft.fft2(image)

fimage = np.log(np.abs(fimage) + 1)

fimage = fimage / np.amax(fimage) * 255

cv2.imwrite("result.png", fimage)

■結果
input.png
FFT input img
result.png
FFT results img

3月 22, 20173月 22, 2017

numpy 行列の積

行列の積の計算サンプル

from numpy import *

a = array([[1,-1],[-2,3]])
b = array([[1,2],[3,4]])
c = dot(a,b)

print "c=",c

from numpy import *

a = array([[1,-1],[-2,3]])

b = array([[1,2],[3,4]])

c = dot(a,b)

print "c=",c

■実行結果
c= [[-2 -2]
[ 7 8]]

※計算内容はこちらをつかわせてもらいました。。

3月 20, 20173月 20, 2017

python用openCVのインストール@Centos7

python2.7でopenCVのインストールをしてみる。
OSはCentos7

コマンドは下記
%yum install opencv-python

実行してみる。入力データの各画素値をダンプするテスト。
ちなみに入力するデータは→

拡大するとこんな感じ↓の5×5ピクセル画像。

import cv2

img = cv2.imread('./test.bmp')

print(img)

import cv2

img = cv2.imread('./test.bmp')

print(img)

■実行結果
[[[255 255 255]
[255 255 255]
[ 0 0 0]
[255 255 255]
[255 255 255]]

[[255 255 255]
[255 255 255]
[ 0 0 0]
[255 255 255]
[255 255 255]]

[[ 0 0 0]
[ 0 0 0]
[ 0 0 0]
[ 0 0 0]
[ 0 0 0]]

[[255 255 255]
[255 255 255]
[ 0 0 0]
[255 255 255]
[255 255 255]]

[[255 255 255]
[255 255 255]
[ 0 0 0]
[255 255 255]
[255 255 255]]]

255:白、0:黒
横走査を下から上に向かって行っている様子が分かる。

3月 5, 20173月 4, 2018

ブラウン運動のシミュレーション可視化

以前ここで試した単純な粒子の中に大きいサイズの粒子を放り込む。周囲から無数の粒子がぶつかりランダムに動くブラウン運動のような動きをみることができる。

■結果
ブラウン運動の可視化

import random
import math
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *

from PIL import Image
from PIL import ImageOps

a  = 2
Dt = 0.01
CUT = 5
#Define xy index
PX = 0
PY = 1
VX = 2
VY = 3
FX = 4
FY = 5
pot = [0,0]
perticle_num = 1000
xy = [[0 for i in range(6)] for j in range(perticle_num)]
BP = [0 for i in range(6)]
Radi  = 0.1

step = 1

def capture():
  global step
  pad_step = '{0:04d}'.format(step)
  print pad_step

  width = glutGet(GLUT_WINDOW_WIDTH)
  height = glutGet(GLUT_WINDOW_HEIGHT)

  glReadBuffer(GL_FRONT)
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
  data = glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE)

  image = Image.fromstring("RGBA", (width, height), data)
  image = ImageOps.flip(image)
  image.save("test"+pad_step+".png")

def find_pair():
  global Radi
  particle_num = len(xy)
  pnum = 0
  w_ratio = 0.1
  while pnum < particle_num:
    dx = xy[pnum][PX] - BP[PX]
    dy = xy[pnum][PY] - BP[PY]

    if dx > 0.5*a:
      dx = dx + a
    if dy > 0.5*a:
      dy = dy + a

    rr = math.sqrt(dx*dx + dy*dy)

    if rr < Radi:
      v2 = math.sqrt(xy[pnum][VX]**2 + xy[pnum][VY]**2)
      cos = (xy[pnum][VX]*dx + xy[pnum][VY]*dy)/(v2*rr)
      sin = math.sqrt(1 - cos**2)

      tmpx= xy[pnum][VX]*(cos**2 - sin**2) - xy[pnum][VY]*(2*cos*sin)
      tmpy= xy[pnum][VX]*(2*cos*sin) + xy[pnum][VY]*(cos**2 - sin**2)

      xy[pnum][VX] =  abs(tmpx) * dx / (abs(dx))
      xy[pnum][VY] =  abs(tmpy) * dy / (abs(dy))
      BP[VX] =  BP[VX] - w_ratio * abs(tmpx) * dx / (abs(dx))
      BP[VY] =  BP[VY] - w_ratio * abs(tmpy) * dy / (abs(dy))

    pnum += 1

def integ():
  find_pair()

  particle_num = len(xy)

  BP[PX] = BP[PX] + Dt*BP[VX]
  BP[PY] = BP[PY] + Dt*BP[VY]

  #boundary condition
  if BP[PX] > a:
     BP[PX] -= a
  if BP[PY] > a:
     BP[PY] -= a
  if BP[PX] < 0:
     BP[PX] += a
  if BP[PY] < 0:
     BP[PY] += a

  pnum = 0
  while pnum < particle_num:
    #update position
    xy[pnum][PX] = xy[pnum][PX] + Dt*xy[pnum][VX]
    xy[pnum][PY] = xy[pnum][PY] + Dt*xy[pnum][VY]

    if xy[pnum][PX] > a:
       xy[pnum][PX] -= a
    if xy[pnum][PY] > a:
       xy[pnum][PY] -= a
    if xy[pnum][PX] < 0:
       xy[pnum][PX] += a
    if xy[pnum][PY] < 0:
       xy[pnum][PY] += a
    pnum += 1


def calc_ena():
    ena = 0.0

    particle_num = len(xy)
    for i in range(0,particle):
       vx2 = xy[i][VX]*xy[i][VX]
       vy2 = xy[i][VY]*xy[i][VY]
       ena = ena + vx2 + vy2

    ena = 0.5*ena
    return ena


def update():
    global Radi
    PI = 3.14159263
    global step

    step = step + 1

    # If you want to get image...
    #capture()

    integ()

    #print step
    nnum = 0
    while nnum < len(xy):
       glPointSize(3.0)
       glColor3f(0.3, 0.3, 1.0)
       glBegin(GL_POINTS)
       glVertex2d(xy[nnum][PX], xy[nnum][PY])
       glEnd()
       nnum = nnum + 1

    N_t = 30
    glColor3f(1.0, 0.0, 0.0)
    glBegin(GL_POLYGON)
    for j in range(0,N_t):
       glVertex2d(Radi*math.cos(2.0*PI*j/N_t)+BP[PX],
                  Radi*math.sin(2.0*PI*j/N_t)+BP[PY])

    glEnd()

def init_set():
  pnum = 0
  xv_sum = 0
  yv_sum = 0
  particle_num = len(xy)
  while pnum < particle_num:
    xy[pnum][PX] = 0  # 0 x-position 
    xy[pnum][PY] = 0  # 1 y-position
    xy[pnum][VX] = random.uniform(-1,1) # 2 x-velocity
    xy[pnum][VY] = random.uniform(-1,1) # 3 y-velocity
    xv_sum += xy[pnum][VX]
    yv_sum += xy[pnum][VY]
    pnum += 1

  xv_sum = xv_sum / particle_num
  yv_sum = yv_sum / particle_num
  pnum = 0

  while pnum < particle_num:
    xy[pnum][VX] = xy[pnum][VX] - xv_sum
    xy[pnum][VY] = xy[pnum][VY] - yv_sum
    pnum += 1

  BP[PX] = a/2
  BP[PY] = a/2
  BP[VX] = random.uniform(-0.5,0.5)
  BP[VY] = random.uniform(-0.5,0.5)


def draw():
    glClearColor(0.0, 0.0, 0.0, 0.0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

    glLoadIdentity()
    glColor3f(1.0,1.0,0.0)
    gluLookAt(a/2, a/2, 4.0  ,a/2 ,a/2 ,0 , 0, 1.0, 0.0)

    glBegin(GL_LINE_LOOP)
    glVertex2d(0,0)
    glVertex2d(0,a)
    glVertex2d(a,a)
    glVertex2d(a,0)
    glEnd()

    update()
    glutSwapBuffers()

def resize(w, h):
    glViewport(0, 0, w, h)
    glLoadIdentity()
    glOrtho(0, a, 0, a, -a, a)

def init():
    glClearColor(0.7, 0.7, 0.7, 0.7)

def idle():
    glutPostRedisplay()

def reshape(w, h):
    glViewport(0, 0,w,h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(30.0, w/h, 1.0, 100.0)
    glMatrixMode (GL_MODELVIEW)


if __name__ == "__main__":

    init_set()

    glutInitWindowPosition(50, 50);
    glutInitWindowSize(340, 340);
    glutInit(sys.argv)
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE )
    glutCreateWindow("pyOpenGL TEST")
    glutDisplayFunc(draw)
    glutReshapeFunc(reshape)
    init()

    glutIdleFunc(idle)
    glutMainLoop()

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

import random

import math

from OpenGL.GL import *

from OpenGL.GLU import *

from OpenGL.GLUT import *

from PIL import Image

from PIL import ImageOps

a = 2

Dt = 0.01

CUT = 5

#Define xy index

PX = 0

PY = 1

VX = 2

VY = 3

FX = 4

FY = 5

pot = [0,0]

perticle_num = 1000

xy = [[0 for i in range(6)] for j in range(perticle_num)]

BP = [0 for i in range(6)]

Radi = 0.1

step = 1

def capture():

global step

pad_step = '{0:04d}'.format(step)

print pad_step

width = glutGet(GLUT_WINDOW_WIDTH)

height = glutGet(GLUT_WINDOW_HEIGHT)

glReadBuffer(GL_FRONT)

glPixelStorei(GL_UNPACK_ALIGNMENT, 1)

data = glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE)

image = Image.fromstring("RGBA", (width, height), data)

image = ImageOps.flip(image)

image.save("test"+pad_step+".png")

def find_pair():

global Radi

particle_num = len(xy)

pnum = 0

w_ratio = 0.1

while pnum < particle_num:

dx = xy[pnum][PX] - BP[PX]

dy = xy[pnum][PY] - BP[PY]

if dx > 0.5*a:

dx = dx + a

if dy > 0.5*a:

dy = dy + a

rr = math.sqrt(dx*dx + dy*dy)

if rr < Radi:

v2 = math.sqrt(xy[pnum][VX]**2 + xy[pnum][VY]**2)

cos = (xy[pnum][VX]*dx + xy[pnum][VY]*dy)/(v2*rr)

sin = math.sqrt(1 - cos**2)

tmpx= xy[pnum][VX]*(cos**2 - sin**2) - xy[pnum][VY]*(2*cos*sin)

tmpy= xy[pnum][VX]*(2*cos*sin) + xy[pnum][VY]*(cos**2 - sin**2)

xy[pnum][VX] = abs(tmpx) * dx / (abs(dx))

xy[pnum][VY] = abs(tmpy) * dy / (abs(dy))

BP[VX] = BP[VX] - w_ratio * abs(tmpx) * dx / (abs(dx))

BP[VY] = BP[VY] - w_ratio * abs(tmpy) * dy / (abs(dy))

pnum += 1

def integ():

find_pair()

particle_num = len(xy)

BP[PX] = BP[PX] + Dt*BP[VX]

BP[PY] = BP[PY] + Dt*BP[VY]

#boundary condition

if BP[PX] > a:

BP[PX] -= a

if BP[PY] > a:

BP[PY] -= a

if BP[PX] < 0:

BP[PX] += a

if BP[PY] < 0:

BP[PY] += a

pnum = 0

while pnum < particle_num:

#update position

xy[pnum][PX] = xy[pnum][PX] + Dt*xy[pnum][VX]

xy[pnum][PY] = xy[pnum][PY] + Dt*xy[pnum][VY]

if xy[pnum][PX] > a:

xy[pnum][PX] -= a

if xy[pnum][PY] > a:

xy[pnum][PY] -= a

if xy[pnum][PX] < 0:

xy[pnum][PX] += a

if xy[pnum][PY] < 0:

xy[pnum][PY] += a

pnum += 1

def calc_ena():

ena = 0.0

particle_num = len(xy)

for i in range(0,particle):

vx2 = xy[i][VX]*xy[i][VX]

vy2 = xy[i][VY]*xy[i][VY]

ena = ena + vx2 + vy2

ena = 0.5*ena

return ena

def update():

global Radi

PI = 3.14159263

global step

step = step + 1

# If you want to get image...

#capture()

integ()

#print step

nnum = 0

while nnum < len(xy):

glPointSize(3.0)

glColor3f(0.3, 0.3, 1.0)

glBegin(GL_POINTS)

glVertex2d(xy[nnum][PX], xy[nnum][PY])

glEnd()

nnum = nnum + 1

N_t = 30

glColor3f(1.0, 0.0, 0.0)

glBegin(GL_POLYGON)

for j in range(0,N_t):

glVertex2d(Radi*math.cos(2.0*PI*j/N_t)+BP[PX],

Radi*math.sin(2.0*PI*j/N_t)+BP[PY])

glEnd()

def init_set():

pnum = 0

xv_sum = 0

yv_sum = 0

particle_num = len(xy)

while pnum < particle_num:

xy[pnum][PX] = 0 # 0 x-position

xy[pnum][PY] = 0 # 1 y-position

xy[pnum][VX] = random.uniform(-1,1) # 2 x-velocity

xy[pnum][VY] = random.uniform(-1,1) # 3 y-velocity

xv_sum += xy[pnum][VX]

yv_sum += xy[pnum][VY]

pnum += 1

xv_sum = xv_sum / particle_num

yv_sum = yv_sum / particle_num

pnum = 0

while pnum < particle_num:

xy[pnum][VX] = xy[pnum][VX] - xv_sum

xy[pnum][VY] = xy[pnum][VY] - yv_sum

pnum += 1

BP[PX] = a/2

BP[PY] = a/2

BP[VX] = random.uniform(-0.5,0.5)

BP[VY] = random.uniform(-0.5,0.5)

def draw():

glClearColor(0.0, 0.0, 0.0, 0.0)

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

glLoadIdentity()

glColor3f(1.0,1.0,0.0)

gluLookAt(a/2, a/2, 4.0 ,a/2 ,a/2 ,0 , 0, 1.0, 0.0)

glBegin(GL_LINE_LOOP)

glVertex2d(0,0)

glVertex2d(0,a)

glVertex2d(a,a)

glVertex2d(a,0)

glEnd()

update()

glutSwapBuffers()

def resize(w, h):

glViewport(0, 0, w, h)

glLoadIdentity()

glOrtho(0, a, 0, a, -a, a)

def init():

glClearColor(0.7, 0.7, 0.7, 0.7)

def idle():

glutPostRedisplay()

def reshape(w, h):

glViewport(0, 0,w,h)

glMatrixMode(GL_PROJECTION)

glLoadIdentity()

gluPerspective(30.0, w/h, 1.0, 100.0)

glMatrixMode (GL_MODELVIEW)

if __name__ == "__main__":

init_set()

glutInitWindowPosition(50, 50);

glutInitWindowSize(340, 340);

glutInit(sys.argv)

glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE )

glutCreateWindow("pyOpenGL TEST")

glutDisplayFunc(draw)

glutReshapeFunc(reshape)

init()

glutIdleFunc(idle)

glutMainLoop()

brownian motion simulation visualization by python and openGL

3月 1, 20173月 4, 2018

pyOpenGLを使って分子動力学を可視化

以前ここで試したmatplotlibを使った簡単な分子動力学計算の可視化処理ですが、描画が遅いのでOpenGLを使って書き直してみた。python用にはPyOpenGLのパッケージが用意されている。結果だがとても速い！

■結果をgifアニメに落としたものが↓。
gifアニメだと実際の描画より遅いので感動が伝わりにくい。。。
openGLを使った可視化

import random
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *

from PIL import Image
from PIL import ImageOps

a  = 10
Dt = 0.1

#Define xy index
PX = 0
PY = 1
VX = 2
VY = 3
FX = 4
FY = 5

perticle_num = 1000
xy = [[0 for i in range(6)] for j in range(perticle_num)]
step = 1

def capture():
  global step
  step = step + 1
  pad_step = '{0:04d}'.format(step)
  print pad_step

  width = glutGet(GLUT_WINDOW_WIDTH)
  height = glutGet(GLUT_WINDOW_HEIGHT)

  glReadBuffer(GL_FRONT)
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
  data = glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE)

  image = Image.fromstring("RGBA", (width, height), data)
  image = ImageOps.flip(image)
  image.save("test"+pad_step+".png")

def integ():
  #verlet integration
  particle_num = len(xy)
  pnum = 0
  while pnum < particle_num:
    #update velocity
    xy[pnum][VX] = xy[pnum][VX] + 0.5*Dt*xy[pnum][FX]
    xy[pnum][VY] = xy[pnum][VY] + 0.5*Dt*xy[pnum][FY]

    #update position
    xy[pnum][PX] = xy[pnum][PX] + Dt*xy[pnum][VX]
    xy[pnum][PY] = xy[pnum][PY] + Dt*xy[pnum][VY]

    #boundary condition
    if xy[pnum][PX] > a:
       xy[pnum][PX] -= a
    if xy[pnum][PY] > a:
       xy[pnum][PY] -= a
    if xy[pnum][PX] < 0:
       xy[pnum][PX] += a
    if xy[pnum][PY] < 0:
       xy[pnum][PY] += a
    pnum += 1


def update():
    # If you want to get image...
    # capture()

    integ()
    nnum = 0
    while nnum < len(xy):
       glPointSize(3.0)
       glColor3f(0.3, 0.3, 1.0)
       glBegin(GL_POINTS)
       glVertex2d(xy[nnum][PX], xy[nnum][PY])
       glEnd()
       nnum = nnum + 1

def init_set():
  pnum = 0
  xv_sum = 0
  yv_sum = 0
  particle_num = len(xy)
  while pnum < particle_num:
    xy[pnum][PX] = 0  # 0 x-position 
    xy[pnum][PY] = 0  # 1 y-position
    xy[pnum][VX] = random.uniform(-1,1) # 2 x-velocity
    xy[pnum][VY] = random.uniform(-1,1) # 3 y-velocity
    xv_sum += xy[pnum][VX]
    yv_sum += xy[pnum][VY]
    xy[pnum][FX] = 0   # 0 x-force
    xy[pnum][FY] = 0   # 1 y-force
    pnum += 1

  xv_sum = xv_sum / particle_num
  yv_sum = yv_sum / particle_num
  pnum = 0
  while pnum < particle_num:
    xy[pnum][VX] = xy[pnum][VX] - xv_sum
    xy[pnum][VY] = xy[pnum][VY] - yv_sum
    pnum += 1
  #exit()

def draw():
    glClearColor(0.0, 0.0, 0.0, 0.0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

    glLoadIdentity()

    glColor3f(1.0,1.0,0.0)
    gluLookAt(a/2, a/2, 20.0  ,a/2 ,a/2 ,0 , 0, 1.0, 0.0)

    glBegin(GL_LINE_LOOP)
    glVertex2d(0,0)
    glVertex2d(0,a)
    glVertex2d(a,a)
    glVertex2d(a,0)
    glEnd()

    update()
    glutSwapBuffers()

def init():
    glClearColor(0.7, 0.7, 0.7, 0.7)

def idle():
    glutPostRedisplay()

def reshape(w, h):
    glViewport(0, 0,w,h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(30.0, w/h, 1.0, 100.0)
    glMatrixMode (GL_MODELVIEW)


if __name__ == "__main__":

    init_set()

    glutInitWindowPosition(50, 50);
    glutInitWindowSize(340, 340);
    glutInit(sys.argv)
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE )
    glutCreateWindow("pyOpenGL TEST")
    glutDisplayFunc(draw)
    glutReshapeFunc(reshape)
    init()

    glutIdleFunc(idle)
    glutMainLoop()

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

import random

from OpenGL.GL import *

from OpenGL.GLU import *

from OpenGL.GLUT import *

from PIL import Image

from PIL import ImageOps

a = 10

Dt = 0.1

#Define xy index

PX = 0

PY = 1

VX = 2

VY = 3

FX = 4

FY = 5

perticle_num = 1000

xy = [[0 for i in range(6)] for j in range(perticle_num)]

step = 1

def capture():

global step

step = step + 1

pad_step = '{0:04d}'.format(step)

print pad_step

width = glutGet(GLUT_WINDOW_WIDTH)

height = glutGet(GLUT_WINDOW_HEIGHT)

glReadBuffer(GL_FRONT)

glPixelStorei(GL_UNPACK_ALIGNMENT, 1)

data = glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE)

image = Image.fromstring("RGBA", (width, height), data)

image = ImageOps.flip(image)

image.save("test"+pad_step+".png")

def integ():

#verlet integration

particle_num = len(xy)

pnum = 0

while pnum < particle_num:

#update velocity

xy[pnum][VX] = xy[pnum][VX] + 0.5*Dt*xy[pnum][FX]

xy[pnum][VY] = xy[pnum][VY] + 0.5*Dt*xy[pnum][FY]

#update position

xy[pnum][PX] = xy[pnum][PX] + Dt*xy[pnum][VX]

xy[pnum][PY] = xy[pnum][PY] + Dt*xy[pnum][VY]

#boundary condition

if xy[pnum][PX] > a:

xy[pnum][PX] -= a

if xy[pnum][PY] > a:

xy[pnum][PY] -= a

if xy[pnum][PX] < 0:

xy[pnum][PX] += a

if xy[pnum][PY] < 0:

xy[pnum][PY] += a

pnum += 1

def update():

# If you want to get image...

# capture()

integ()

nnum = 0

while nnum < len(xy):

glPointSize(3.0)

glColor3f(0.3, 0.3, 1.0)

glBegin(GL_POINTS)

glVertex2d(xy[nnum][PX], xy[nnum][PY])

glEnd()

nnum = nnum + 1

def init_set():

pnum = 0

xv_sum = 0

yv_sum = 0

particle_num = len(xy)

while pnum < particle_num:

xy[pnum][PX] = 0 # 0 x-position

xy[pnum][PY] = 0 # 1 y-position

xy[pnum][VX] = random.uniform(-1,1) # 2 x-velocity

xy[pnum][VY] = random.uniform(-1,1) # 3 y-velocity

xv_sum += xy[pnum][VX]

yv_sum += xy[pnum][VY]

xy[pnum][FX] = 0 # 0 x-force

xy[pnum][FY] = 0 # 1 y-force

pnum += 1

xv_sum = xv_sum / particle_num

yv_sum = yv_sum / particle_num

pnum = 0

while pnum < particle_num:

xy[pnum][VX] = xy[pnum][VX] - xv_sum

xy[pnum][VY] = xy[pnum][VY] - yv_sum

pnum += 1

#exit()

def draw():

glClearColor(0.0, 0.0, 0.0, 0.0)

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

glLoadIdentity()

glColor3f(1.0,1.0,0.0)

gluLookAt(a/2, a/2, 20.0 ,a/2 ,a/2 ,0 , 0, 1.0, 0.0)

glBegin(GL_LINE_LOOP)

glVertex2d(0,0)

glVertex2d(0,a)

glVertex2d(a,a)

glVertex2d(a,0)

glEnd()

update()

glutSwapBuffers()

def init():

glClearColor(0.7, 0.7, 0.7, 0.7)

def idle():

glutPostRedisplay()

def reshape(w, h):

glViewport(0, 0,w,h)

glMatrixMode(GL_PROJECTION)

glLoadIdentity()

gluPerspective(30.0, w/h, 1.0, 100.0)

glMatrixMode (GL_MODELVIEW)

if __name__ == "__main__":

init_set()

glutInitWindowPosition(50, 50);

glutInitWindowSize(340, 340);

glutInit(sys.argv)

glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE )

glutCreateWindow("pyOpenGL TEST")

glutDisplayFunc(draw)

glutReshapeFunc(reshape)

init()

glutIdleFunc(idle)

glutMainLoop()

3月 1, 20173月 4, 2018

pythonでopenGLを試す

先日matplotlibを使った簡単な分子動力学の可視化を試したが非常に描画が遅い。ググってみるとどうもmatplotlibはプロッティングの遅さに定評があるらしい。

そんなわけで違う方法での可視化を試す。
試してみるのはopenGL。python用にはpyOpenGLというパッケージが用意されている。当方の環境centos7では下記コマンドで導入が出来た。

%easy_install PyOpenGL

from OpenGL.GL import *
from OpenGL.GLUT import *


def draw():
    glClearColor(1.0, 0.0, 0.0, 0.0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glFlush()
    glutSwapBuffers()

if __name__ == "__main__":
    glutInit(sys.argv)
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
    glutInitWindowSize(320, 240)
    glutCreateWindow("openGL test")
    glutDisplayFunc(draw)

    glutMainLoop()

from OpenGL.GL import *

from OpenGL.GLUT import *

def draw():

glClearColor(1.0, 0.0, 0.0, 0.0)

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

glFlush()

glutSwapBuffers()

if __name__ == "__main__":

glutInit(sys.argv)

glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)

glutInitWindowSize(320, 240)

glutCreateWindow("openGL test")

glutDisplayFunc(draw)

glutMainLoop()

■実行結果
pyopenglのテスト