Matplotlib相当于pygame翻转
问题内容：
我有一个带有快速动画的程序，该程序可以在pygame下完美运行，并且出于技术原因，我只需要使用matplotlib或其他广泛使用的模块来进行相同的操作。
程序结构大致如下：
pygame.init()
SURF = pygame.display.set_mode((500, 500))
arr = pygame.surfarray.pixels2d(SURF) # a view for numpy, as a 2D array
while ok:
# modify some pixels of arr
pygame.display.flip()
pygame.quit()
我没有低级的matplotlib经验，但是我认为可以用matplotlib做等效的事情。换一种说法 ：
如何共享图形的位图，修改一些像素并刷新屏幕？
这是一个最小的工作示例，它在我的计算机上每秒翻转250帧（比屏幕还快…）：
import pygame,numpy,time
pygame.init()
size=(400,400)
SURF = pygame.display.set_mode(size)
arr = pygame.surfarray.pixels2d(SURF) # buffer pour numpy
t0=time.clock()
for counter in range(1000):
arr[:]=numpy.random.randint(0,0xfffff,size)
pygame.display.flip()
pygame.quit()
print(counter/(time.clock()-t0))
编辑
我尝试用答案中的指示：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
fig = plt.figure()
def f(x, y):
return np.sin(x) + np.cos(y)
x = np.linspace(0, 2 * np.pi, 400)
y = np.linspace(0, 2 * np.pi, 400).reshape(-1, 1)
im = plt.imshow(f(x, y), animated=True)
count=0
t0=time.clock()+1
def updatefig(*args):
global x, y,count,t0
x += np.pi / 15.
y += np.pi / 20.
im.set_array(f(x, y))
if time.clock()<t0:
count+=1
else:
print (count)
count=0
t0=time.clock()+1
return im,
ani = animation.FuncAnimation(fig, updatefig, interval=50, blit=True)
plt.show()
但这只能提供20 fps。…
问题答案：
应该注意的是，人脑能够“看到”高达25 fps的帧速率。更快的更新实际上并未解决。
Matplotlib
使用matplotlib及其animation模块，问题示例在我的计算机上以 84 fps的速度 运行。
import time
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
fig, ax = plt.subplots()
def f(x, y):
return np.sin(x) + np.cos(y)
x = np.linspace(0, 2 * np.pi, 400)
y = np.linspace(0, 2 * np.pi, 400).reshape(-1, 1)
im = ax.imshow(f(x, y), animated=True)
text = ax.text(200,200, "")
class FPS():
def __init__(self, avg=10):
self.fps = np.empty(avg)
self.t0 = time.clock()
def tick(self):
t = time.clock()
self.fps[1:] = self.fps[:-1]
self.fps[0] = 1./(t-self.t0)
self.t0 = t
return self.fps.mean()
fps = FPS(100)
def updatefig(i):
global x, y
x += np.pi / 15.
y += np.pi / 20.
im.set_array(f(x, y))
tx = 'Mean Frame Rate:\n {fps:.3f}FPS'.format(fps= fps.tick() )
text.set_text(tx)
return im, text,
ani = animation.FuncAnimation(fig, updatefig, interval=1, blit=True)
plt.show()
PyQtGraph
在pyqtgraph中，可以获得更高的帧速率，它将在我的计算机上以 295 fps的速度 运行。
import sys
import time
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
import pyqtgraph as pg
class FPS():
def __init__(self, avg=10):
self.fps = np.empty(avg)
self.t0 = time.clock()
def tick(self):
t = time.clock()
self.fps[1:] = self.fps[:-1]
self.fps[0] = 1./(t-self.t0)
self.t0 = t
return self.fps.mean()
fps = FPS(100)
class App(QtGui.QMainWindow):
def __init__(self, parent=None):
super(App, self).__init__(parent)
#### Create Gui Elements ###########
self.mainbox = QtGui.QWidget()
self.setCentralWidget(self.mainbox)
self.mainbox.setLayout(QtGui.QVBoxLayout())
self.canvas = pg.GraphicsLayoutWidget()
self.mainbox.layout().addWidget(self.canvas)
self.label = QtGui.QLabel()
self.mainbox.layout().addWidget(self.label)
self.view = self.canvas.addViewBox()
self.view.setAspectLocked(True)
self.view.setRange(QtCore.QRectF(0,0, 100, 100))
# image plot
self.img = pg.ImageItem(border='w')
self.view.addItem(self.img)
#### Set Data #####################
self.x = np.linspace(0, 2 * np.pi, 400)
self.y = np.linspace(0, 2 * np.pi, 400).reshape(-1, 1)
#### Start #####################
self._update()
def f(self, x, y):
return np.sin(x) + np.cos(y)
def _update(self):
self.x += np.pi / 15.
self.y += np.pi / 20.
self.img.setImage(self.f(self.x, self.y))
tx = 'Mean Frame Rate:\n {fps:.3f}FPS'.format(fps= fps.tick() )
self.label.setText(tx)
QtCore.QTimer.singleShot(1, self._update)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
thisapp = App()
thisapp.show()
sys.exit(app.exec_())
