I'm new to matplotlib and can't find out how to update my plot once I enter new values for the lines displayed in the plot. Showing the plots with the values that I entered first works without an issue.
main.py
from two_dof_plotter import MechanismPlotter
import time
# Create an object of MechanismPlotter
two_dof_robot_plot = MechanismPlotter(0.25, 0.3, 0.1, 0, 0)
two_dof_robot_plot.start_plot()
two_dof_robot_plot.draw_required_work_envelope(0, 0)
two_dof_robot_plot.draw_mechanism_with_inverse_kinematic(0.5, -0.0375)
two_dof_robot_plot.show_plot()
time.sleep(2)
two_dof_robot_plot.draw_mechanism_with_inverse_kinematic(0.2, -0.0375)
two_dof_plotter.py
import matplotlib.pyplot as plt
import numpy as np
class MechanismPlotter:
def __init__(self, upper_arm_length, lower_arm_length, lever_arm_length, gripper_x_offset, gripper_y_offset):
self.lower_arm_length = lower_arm_length
self.upper_arm_length = upper_arm_length
self.lever_arm_length = lever_arm_length
self.gripper_x_offset = gripper_x_offset
self.gripper_y_offset = gripper_y_offset
self.ploted_lines = []
self.fig, self.ax = plt.subplots()
def start_plot(self):
self.ax.set_aspect('equal')
self.ax.set_xlim(-0.6, 0.6)
self.ax.set_ylim(-0.6,0.6)
self.ax.set_xlabel('X')
self.ax.set_ylabel('Y')
plt.grid(True)
def draw_mechanism_with_forward_kinematic(self, upper_arm_angle, lower_arm_angle):
# Calculate the coordinates of the lower and upper arm endpoints
upper_arm_x = self.upper_arm_length * np.cos(upper_arm_angle)
upper_arm_y = self.upper_arm_length * np.sin(upper_arm_angle)
lower_arm_x = upper_arm_x + self.lower_arm_length * np.cos(lower_arm_angle)
lower_arm_y = upper_arm_y + self.lower_arm_length * np.sin(lower_arm_angle)
lever_arm_x = -(self.lever_arm_length * np.cos(lower_arm_angle))
lever_arm_y = -(self.lever_arm_length * np.sin(lower_arm_angle))
# Plot the lines
if len(self.ploted_lines) > 0:
self.ploted_lines[0].set_data([0, upper_arm_x], [0, upper_arm_y])
self.ploted_lines[1].set_data([upper_arm_x, lower_arm_x], [upper_arm_y, lower_arm_y])
self.ploted_lines[2].set_data([0, lever_arm_x], [0, lever_arm_y])
self.ploted_lines[3].set_data([upper_arm_x, upper_arm_x + lever_arm_x], [upper_arm_y, upper_arm_y + lever_arm_y])
self.ploted_lines[4].set_data([lever_arm_x, upper_arm_x + lever_arm_x], [lever_arm_y, upper_arm_y + lever_arm_y])
# Draw the updated plot
self.fig.canvas.draw()
else:
# Plot the lines
line1, = self.ax.plot([0, upper_arm_x], [0, upper_arm_y], 'b-', linewidth=2)
line2, = self.ax.plot([upper_arm_x, lower_arm_x], [upper_arm_y, lower_arm_y], 'r-', linewidth=2)
line3, = self.ax.plot([0, lever_arm_x], [0, lever_arm_y], 'g-', linewidth=1)
line4, = self.ax.plot([upper_arm_x, upper_arm_x + lever_arm_x], [upper_arm_y, upper_arm_y + lever_arm_y], 'g-', linewidth=1)
line5, = self.ax.plot([lever_arm_x, upper_arm_x + lever_arm_x], [lever_arm_y, upper_arm_y + lever_arm_y], 'g-', linewidth=1)
# Add the lines to the list of lines to remove
self.ploted_lines.extend([line1, line2, line3, line4, line5])
# Calculate the distance between the upper arm and the mechanism for the lower arm
distance = np.sin(np.pi-(-lower_arm_angle)-upper_arm_angle) * self.lever_arm_length
def draw_mechanism_with_inverse_kinematic(self, x, y):
# Calculate the inverse kinematic angles
x = x - self.gripper_x_offset
y = y - self.gripper_y_offset
c = np.sqrt(x**2 + y**2)
upper_arm_angle = np.arccos((self.upper_arm_length**2 + c**2 - self.lower_arm_length**2) / (2 * self.upper_arm_length * c)) + np.arctan(y/x)
lower_arm_angle = upper_arm_angle + np.arccos((self.lower_arm_length**2 + self.upper_arm_length**2 - c**2) / (2 * self.lower_arm_length * self.upper_arm_length)) - np.pi
# Draw the mechanism
ploted_lines = self.draw_mechanism_with_forward_kinematic(upper_arm_angle, lower_arm_angle)
def remove_ploted_mechanism(self, ploted_lines):
for line in ploted_lines:
line.remove()
self.ax.clear()
self.fig.canvas.draw()
def draw_required_work_envelope(self, x_por_offset, y_por_offset):
# Define the coordinates of the work envelope points
x = [0.16+x_por_offset, 0.16+x_por_offset, 0.5+x_por_offset, 0.32+x_por_offset, 0.16+x_por_offset,]
y = [0.06-y_por_offset, -0.0375-y_por_offset, -0.0375-y_por_offset, 0.06-y_por_offset, 0.06-y_por_offset,]
# Plot the work envelope
self.ax.fill_between(x, y, color='skyblue', alpha=0.5)
def show_plot(self):
plt.show()
what do i have to do to update it correctly after calling the method draw_mechanism_with_forward_kinematic a second time?
I already tried different implementations of the draw() function and tried with the .ion(), but so far I haven't found where my issue is.
as I see it you have 3 options:
plt.show()
at the very endplt.show(block=False)
plt.ion()
at the very beginning of the script) to avoid blocking the terminal in generalFor interactive-mode, see: https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.isinteractive.html#matplotlib.pyplot.isinteractive