更新时间:2023-02-26 17:17:21
如果您想绘制实时数据并希望避免使用其他库来为您执行此操作,您可能会发现以下内容是一个启发性的起点创建自己的图表.该示例在评估标准库中的 math.sin
函数时绘制了一整圈值.代码会根据需要考虑自动采样、调整大小和更新,并且应该具有相当的响应能力.
If you want to graph your live data and want to avoid using other libraries to do that for you, you might find the following to be an enlightening starting point for creating your own graphs. The sample draws a full circle of values when evaluating the math.sin
function that comes in the standard library. The code takes into account automatic sampling, resizing, and updating as needed and should be fairly responsive.
#! /usr/bin/env python3
import math
import threading
import time
import tkinter.ttk
import uuid
from tkinter.constants import EW, NSEW, SE
class Application(tkinter.ttk.Frame):
FPS = 10 # frames per second used to update the graph
MARGINS = 10, 10, 10, 10 # internal spacing around the graph
@classmethod
def main(cls):
tkinter.NoDefaultRoot()
root = tkinter.Tk()
root.title('Tkinter Graphing')
# noinspection SpellCheckingInspection
root.minsize(640, 480) # VGA (NTSC)
cls(root).grid(sticky=NSEW)
root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)
root.mainloop()
def __init__(self, master=None, **kw):
super().__init__(master, **kw)
self.display = tkinter.Canvas(self, background='white')
self.display.bind('<Configure>', self.draw)
self.start = StatefulButton(self, 'Start Graphing', self.start_graph)
self.grip = tkinter.ttk.Sizegrip(self)
self.grid_widgets(padx=5, pady=5)
self.data_source = DataSource()
self.after_idle(self.update_graph, round(1000 / self.FPS))
self.run_graph = None
def grid_widgets(self, **kw):
self.display.grid(row=0, column=0, columnspan=2, sticky=NSEW, **kw)
self.start.grid(row=1, column=0, sticky=EW, **kw)
self.grip.grid(row=1, column=1, sticky=SE)
self.grid_rowconfigure(0, weight=1)
self.grid_columnconfigure(0, weight=1)
def start_graph(self):
self.run_graph = True
threading.Thread(target=self.__simulate, daemon=True).start()
return 'Stop Graphing', self.stop_graph
def stop_graph(self):
self.run_graph = False
return 'Clear Graph', self.clear_graph
def clear_graph(self):
self.data_source.clear()
self.reset_display()
return 'Start Graphing', self.start_graph
# def __simulate(self):
# # simulate changing populations
# for population in itertools.count():
# if not self.run_graph:
# break
# self.data_source.append(population, get_max_age(population, 200))
# def __simulate(self):
# # simulate changing ages
# for age in itertools.count(1):
# if not self.run_graph:
# break
# self.data_source.append(age, get_max_age(250_000_000, age))
def __simulate(self):
# draw a sine curve
for x in range(800):
time.sleep(0.01)
if not self.run_graph:
break
self.data_source.append(x, math.sin(x * math.pi / 400))
def update_graph(self, rate, previous_version=None):
if previous_version is None:
self.reset_display()
current_version = self.data_source.version
if current_version != previous_version:
data_source = self.data_source.copy()
self.draw(data_source)
self.after(rate, self.update_graph, rate, current_version)
def reset_display(self):
self.display.delete('data')
self.display.create_line((0, 0, 0, 0), tag='data', fill='black')
def draw(self, data_source):
if not isinstance(data_source, DataSource):
data_source = self.data_source.copy()
if data_source:
self.display.coords('data', *data_source.frame(
self.MARGINS,
self.display.winfo_width(),
self.display.winfo_height(),
True
))
class StatefulButton(tkinter.ttk.Button):
def __init__(self, master, text, command, **kw):
kw.update(text=text, command=self.__do_command)
super().__init__(master, **kw)
self.__command = command
def __do_command(self):
self['text'], self.__command = self.__command()
def new(obj):
kind = type(obj)
return kind.__new__(kind)
def interpolate(x, y, z):
return x * (1 - z) + y * z
def interpolate_array(array, z):
if z <= 0:
return array[0]
if z >= 1:
return array[-1]
share = 1 / (len(array) - 1)
index = int(z / share)
x, y = array[index:index + 2]
return interpolate(x, y, z % share / share)
def sample(array, count):
scale = count - 1
return tuple(interpolate_array(array, z / scale) for z in range(count))
class DataSource:
EMPTY = uuid.uuid4()
def __init__(self):
self.__x = []
self.__y = []
self.__version = self.EMPTY
self.__mutex = threading.Lock()
@property
def version(self):
return self.__version
def copy(self):
instance = new(self)
with self.__mutex:
instance.__x = self.__x.copy()
instance.__y = self.__y.copy()
instance.__version = self.__version
instance.__mutex = threading.Lock()
return instance
def __bool__(self):
return bool(self.__x or self.__y)
def frame(self, margins, width, height, auto_sample=False, timing=False):
if timing:
start = time.perf_counter()
x1, y1, x2, y2 = margins
drawing_width = width - x1 - x2
drawing_height = height - y1 - y2
with self.__mutex:
x_tuple = tuple(self.__x)
y_tuple = tuple(self.__y)
if auto_sample and len(x_tuple) > drawing_width:
x_tuple = sample(x_tuple, drawing_width)
y_tuple = sample(y_tuple, drawing_width)
max_y = max(y_tuple)
x_scaling_factor = max(x_tuple) - min(x_tuple)
y_scaling_factor = max_y - min(y_tuple)
coords = tuple(
coord
for x, y in zip(x_tuple, y_tuple)
for coord in (
round(x1 + drawing_width * x / x_scaling_factor),
round(y1 + drawing_height * (max_y - y) / y_scaling_factor)))
if timing:
# noinspection PyUnboundLocalVariable
print(f'len = {len(coords) >> 1}; '
f'sec = {time.perf_counter() - start:.6f}')
return coords
def append(self, x, y):
with self.__mutex:
self.__x.append(x)
self.__y.append(y)
self.__version = uuid.uuid4()
def clear(self):
with self.__mutex:
self.__x.clear()
self.__y.clear()
self.__version = self.EMPTY
def extend(self, iterable):
with self.__mutex:
for x, y in iterable:
self.__x.append(x)
self.__y.append(y)
self.__version = uuid.uuid4()
if __name__ == '__main__':
Application.main()