working example

This commit is contained in:
Didictateur 2026-02-15 17:15:25 +01:00
parent 431570ce73
commit d2f533dce9
2 changed files with 153 additions and 10 deletions

View file

@ -1,21 +1,59 @@
import legrandchien as lgc
import matplotlib.pyplot as plt
import matplotlib.animation as animation
if __name__ == "__main__":
g = lgc.Const(-10)
g = lgc.Const(10)
m = lgc.Const(1)
x = lgc.Var("x")
y = lgc.Var("y")
T = 0.5 * m * x.diff() * x.diff()
V = m * g * x
T = 0.5 * m * (x.diff() * x.diff() + y.diff() * y.diff())
V = m * g * y
L = T - V
dL = L.diff()
dico = {
"x" : 0,
"d_x" : 1,
"d_d_x" : 1,
"y" : 0,
"d_y" : 1
}
print(dL.evaluate(dico))
values = L.solve(dico, 10, 0.1)
# Extraire les données pour x et y
times = sorted(values.keys())
positions_x = [values[t]["x"] for t in times]
positions_y = [values[t]["y"] for t in times]
# Créer la figure
fig, ax = plt.subplots(figsize=(8, 8))
ax.set_xlim(min(positions_x) - 5, max(positions_x) + 5)
ax.set_ylim(min(positions_y) - 5, max(positions_y) + 5)
ax.set_xlabel("X (m)")
ax.set_ylabel("Y (m)")
ax.grid(True)
# Point animé
point, = ax.plot([], [], 'ro', markersize=15, label="Particule")
# Trajectoire
line, = ax.plot([], [], 'b-', alpha=0.3, linewidth=2, label="Trajectoire")
# Texte temps
time_text = ax.text(0.02, 0.95, '', transform=ax.transAxes, fontsize=12)
ax.legend()
def animate(frame):
# Point courant
point.set_data([positions_x[frame]], [positions_y[frame]])
# Trajectoire jusqu'au point courant
line.set_data(positions_x[:frame + 1], positions_y[:frame + 1])
# Texte
time_text.set_text(f"t = {times[frame]:.2f}s\nx = {positions_x[frame]:.2f}m, y = {positions_y[frame]:.2f}m")
return point, line, time_text
ani = animation.FuncAnimation(fig, animate, frames=len(times),
interval=50, blit=True, repeat=True)
plt.show()

View file

@ -186,10 +186,20 @@ class Var:
return Var(self.name, self.degree)
def diff(self, n=1):
return Var("d_"+self.name, self.degree+n)
return Var("d_"*n+self.name, self.degree+n)
def evaluate(self, dico):
return dico[self.name]
def __eq__(self, other):
if isinstance(other, str):
return False
if not (self.type == "Var" and other.type == "Var"):
return False
return self.name == other.name and self.degree == other.degree
def __hash__(self):
return hash((self.name, self.degree))
def __add__(self, other):
if other.type == "Const":
@ -350,9 +360,9 @@ class Equation:
def copy(self):
if self.op == Operation.CONST:
return Const(self.value.value)
return Equation(Operation.CONST, None, None, Const(self.value.value))
if self.op == Operation.VAR:
return Var(self.value.name, self.value.degree)
return Equation(Operation.VAR, None, None, Var(self.value.name, self.value.degree))
return Equation(self.op, self.left.copy(), self.right.copy(), None)
def diff(self):
@ -402,6 +412,101 @@ class Equation:
if self.op == Operation.DIV:
return self.left.evaluate(dico) / self.right.evaluate(dico)
def solve(self, dico, tmax=10, dt=0.01):
variables = self.getAllVar()
equations = []
print([v.name for v in variables])
for var in variables:
equations.append(self.partial(var.diff().name).diff() - self.partial(var.name))
unknown = self.getUnknown(dico)
for eq in equations:
unknown = unknown.union(eq.getUnknown(dico))
t = 0
values = {t : {var.name : dico[var.name] for var in variables}}
for var in unknown:
dico[var.name] = 0.
assert(len(unknown) == len(equations))
n = len(unknown)
variables = list(variables)
unknown = list(unknown)
equations = list(equations)
while t <= tmax:
err = 1
while err > 10**-6:
# jacobian
J = np.zeros((n, n))
F = np.zeros(n)
for i in range(n):
F[i] = equations[i].evaluate(dico)
for j in range(n):
# print(equations[0])
J[i][j] = equations[i].partial(unknown[j].name).evaluate(dico)
# print(J, F)
err = np.linalg.norm(F)
dX = -np.linalg.inv(J).dot(F)
for i in range(n):
dico[unknown[i].name] += dX[i]
values[t] = {var.name : dico[var.name] for var in variables}
t += dt
# update all values
for i in range(n):
var = unknown[i]
d = var.degree
name = var.name
while d > 0:
ivar_name = name[2:]
dico[ivar_name] += dt * dico[name]
d -= 1
name = ivar_name
return values
def getAllVar(self):
if self.op == Operation.CONST:
return set()
if self.op == Operation.VAR:
if self.value.degree == 0:
return {self.value.copy()}
else:
return {Var(self.value.name[2*self.value.degree:], 0)}
return self.left.getAllVar().union(self.right.getAllVar())
def getUnknown(self, dico):
if self.op == Operation.CONST:
return set()
if self.op == Operation.VAR:
if self.value.name not in dico:
return {self.value}
return set()
return self.left.getUnknown(dico).union(self.right.getUnknown(dico))
def __str__(self):
if self.op == Operation.CONST:
return str(self.value.value)
if self.op == Operation.VAR:
return self.value.name
if self.op == Operation.ADD:
return f"{str(self.left)} + {str(self.right)}"
if self.op == Operation.SUB:
return f"{str(self.left)} - {str(self.right)}"
if self.op == Operation.MULT:
return f"({str(self.left)})*({str(self.right)})"
if self.op == Operation.DIV:
return f"({str(self.left)})/({str(self.right)})"
def __add__(self, other):
if other.type == "Const":