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ENH: Improve draw method to raise warnings correctly and move to plot…
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…s file

Plus, some improvements to docs
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@MateusStano
MateusStano committed Sep 20, 2023
1 parent 15303d7 commit 7937d7d
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230 changes: 110 additions & 120 deletions rocketpy/AeroSurface.py
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Original file line number Diff line number Diff line change
@@ -1,11 +1,12 @@
from abc import ABC, abstractmethod
import warnings

import numpy as np

from .Function import Function
import matplotlib.pyplot as plt
import numpy as np
from scipy.optimize import root_scalar
from scipy.optimize import fsolve
from .plots.aero_surface_plots import (
_EllipticalFinsPlots,
_NoseConePlots,
Expand Down Expand Up @@ -136,7 +137,7 @@ def __init__(
length,
kind,
base_radius=None,
bluffness=0.0,
bluffness=None,
rocket_radius=None,
name="Nose Cone",
):
Expand All @@ -156,7 +157,8 @@ def __init__(
``rocket_radius`` will be assumed as 1.
bluffness : float, optional
Ratio between the radius of the circle on the tip of the ogive and
the radius of the base of the ogive.
the radius of the base of the ogive. Currently only used for the
nose cone's drawing. Must be between 0 and 1.
rocket_radius : int, float, optional
The reference rocket radius used for lift coefficient normalization.
If not given, the ratio between ``base_radius`` and
Expand All @@ -174,12 +176,10 @@ def __init__(
self._rocket_radius = rocket_radius
self._base_radius = base_radius
self._length = length
self._bluffness = bluffness
self.bluffness = bluffness
self.kind = kind

self.evaluate_geometrical_parameters()
self.evaluate_lift_coefficient()
self.evaluate_center_of_pressure()

self.plots = _NoseConePlots(self)
self.prints = _NoseConePrints(self)
Expand Down Expand Up @@ -290,75 +290,20 @@ def kind(self, value):
+ '\n\t"parabolic"\n'
)

n = 127 # Points on the final curve.
p = 3 # Density modifier. Greater n makes more points closer to 0. n=1 -> points equally spaced.

# Finds the tangential intersection point between the circle and nosecone curve.
y_prime_nosecone = lambda x: self.y_nosecone.differentiate(x)
x_intercept = lambda x: x + self.y_nosecone(x) * y_prime_nosecone(x)
radius = lambda x: (self.y_nosecone(x) ** 2 + (x - x_intercept(x)) ** 2) ** 0.5

# Circle radius
r = self.bluffness * self.base_radius

# Sets up a circle at the starting position to test bluffness
test_circle = lambda x: np.sqrt(x * r - x**2)

# Checks bluffness circle an chooses to use it or not
if test_circle(1e-03) > self.y_nosecone(1e-03):
# Finds intersection point between circle and nosecone curve
x_init = root_scalar(
lambda x: radius(x) - self.bluffness * self.base_radius,
bracket=[1e-6, self.length],
method="brenth",
x0=self.bluffness * self.base_radius,
xtol=1e-6,
).root
circle_center = x_intercept(x_init)
else:
# Sets up parameters to continue calculus without bluffness
r = 0
circle_center = 0
x_init = 0

# Warning in case user tried to use bluffness and it was ignored
if self.bluffness != 0:
print(
"WARNING: The chosen bluffness ratio is insufficient for "
"the selected nosecone category, thereby the effective "
"bluffness will be 0."
)

# Creates the circle at correct position.
circle = lambda x: abs(r**2 - (x - circle_center) ** 2) ** 0.5

# Function defining final shape of curve with circle o the tip.
final_shape = Function(
lambda x: self.y_nosecone(x) if x >= x_init else circle(x)
)
final_shape_vec = np.vectorize(final_shape)

# Creates the vectors X and Y with the points of the curve.
self.nosecone_x = (self.length - (circle_center - r)) * (
np.linspace(0, 1, n) ** p
)
self.nosecone_y = final_shape_vec(self.nosecone_x + (circle_center - r))

# Evaluates final geometry parameters.
self.length = self.nosecone_x[-1]
self.fineness_ratio = self.length / (2 * self.base_radius)
self.evaluate_center_of_pressure()
self.evaluate_geometrical_parameters()

@property
def bluffness(self):
return self._bluffness

@bluffness.setter
def bluffness(self, value):
if value > 1 or value < 0:
raise ValueError(
f"Bluffness ratio {value} out of range. It must be between 0 and 1."
)
if value is not None:
if value > 1 or value < 0:
raise ValueError(
f"Bluffness ratio of {value} is out of range. It must be between 0 and 1."
)
self._bluffness = value

def evaluate_geometrical_parameters(self):
Expand All @@ -368,11 +313,94 @@ def evaluate_geometrical_parameters(self):
-------
None
"""

# If base radius is not given, the ratio between base radius and
# rocket radius is assumed as 1, meaning that the nose cone has the
# same radius as the rocket
if self.base_radius is None or self.rocket_radius is None:
self.radius_ratio = 1
# If base radius is given, the ratio between base radius and rocket
# radius is calculated
else:
self.radius_ratio = self.base_radius / self.rocket_radius

self.fineness_ratio = self.length / (2 * self.base_radius)
return None

def evaluate_nose_shape(self):
"""Calculates and saves nose cone's shape. The shape is saved as two
vectors, one for the x coordinates and one for the y coordinates.
Returns
-------
None
"""
# Constants
n = 127 # Points on the final curve.
p = 3 # Density modifier. Greater n makes more points closer to 0. n=1 -> points equally spaced.

# Calculate a function to find the tangential intersection point between the circle and nosecone curve.
def find_x_intercept(x):
return x + self.y_nosecone(x) * self.y_nosecone.differentiate(x)

# Calculate a function to find the radius of the nosecone curve
def find_radius(x):
return (self.y_nosecone(x) ** 2 + (x - find_x_intercept(x)) ** 2) ** 0.5

# Check bluffness circle and choose whether to use it or not
if self.bluffness is None or self.bluffness == 0:
# Set up parameters to continue without bluffness
r_circle, circle_center, x_init = 0, 0, 0
else:
# Calculate circle radius
r_circle = self.bluffness * self.base_radius
if self.kind == "elliptical":
# Calculate a function to set up a circle at the starting position to test bluffness
def test_circle(x):
return np.sqrt(r_circle**2 - (x - r_circle) ** 2)

# Check if bluffness circle is too small
if test_circle(1e-03) <= self.y_nosecone(1e-03):
# Raise a warning
warnings.warn(
"WARNING: The chosen bluffness ratio is too small for "
"the selected nose cone category, thereby the effective "
"bluffness will be 0."
)
# Set up parameters to continue without bluffness
r_circle, circle_center, x_init = 0, 0, 0
else:
# Find the intersection point between circle and nosecone curve
x_init = fsolve(lambda x: find_radius(x) - r_circle, r_circle)[0]
circle_center = find_x_intercept(x_init)
else:
# Find the intersection point between circle and nosecone curve
x_init = fsolve(lambda x: find_radius(x) - r_circle, r_circle)[0]
circle_center = find_x_intercept(x_init)

# Calculate a function to create the circle at the correct position
def create_circle(x):
return abs(r_circle**2 - (x - circle_center) ** 2) ** 0.5

# Define a function for the final shape of the curve with a circle at the tip
def final_shape(x):
return self.y_nosecone(x) if x >= x_init else create_circle(x)

# Vectorize the final_shape function
final_shape_vec = np.vectorize(final_shape)

# Create the vectors X and Y with the points of the curve
self.nosecone_x = (self.length - (circle_center - r_circle)) * (
np.linspace(0, 1, n) ** p
)
self.nosecone_y = final_shape_vec(self.nosecone_x + (circle_center - r_circle))

# Evaluate final geometry parameters
self.length = self.nosecone_x[-1]
self.fineness_ratio = self.length / (2 * self.base_radius)

return None

def evaluate_lift_coefficient(self):
"""Calculates and returns nose cone's lift coefficient.
The lift coefficient is saved and returned. This function
Expand Down Expand Up @@ -418,60 +446,14 @@ def evaluate_center_of_pressure(self):
return self.cp

def draw(self):
# Figure creation and set up
fig_ogive, ax = plt.subplots()
ax.set_xlim(-0.05, self.length * 1.02) # Horizontal size
ax.set_ylim(-self.base_radius * 1.05, self.base_radius * 1.05) # Vertical size
ax.set_aspect("equal") # Makes the graduation be the same on both axis
ax.set_facecolor("#EEEEEE") # Background color
ax.grid(True, linestyle="--", linewidth=0.5)

cp_plot = (self.cpz, 0)
# Plotting
ax.plot(
self.nosecone_x, self.nosecone_y, linestyle="-", color="#A60628"
) # Ogive's upper side
ax.plot(
self.nosecone_x, -self.nosecone_y, linestyle="-", color="#A60628"
) # Ogive's lower side
ax.scatter(
*cp_plot, label="Center Of Pressure", color="red", s=100, zorder=10
) # Center of pressure inner circle
ax.scatter(
*cp_plot, facecolors="none", edgecolors="red", s=500, zorder=10
) # Center of pressure outer circle
# Center Line
ax.plot(
[0, self.nosecone_x[len(self.nosecone_x) - 1]],
[0, 0],
linestyle="--",
color="#7A68A6",
linewidth=1.5,
label="Center Line",
)
# Vertical base line
ax.plot(
[
self.nosecone_x[len(self.nosecone_x) - 1],
self.nosecone_x[len(self.nosecone_x) - 1],
],
[
self.nosecone_y[len(self.nosecone_y) - 1],
-self.nosecone_y[len(self.nosecone_y) - 1],
],
linestyle="-",
color="#A60628",
linewidth=1.5,
)
"""Draw the fin shape along with some important information, including
the center line, the quarter line and the center of pressure position.
# Labels and legend
ax.set_xlabel("Length")
ax.set_ylabel("Radius")
ax.set_title(self.kind + " Nose Cone")
ax.legend(bbox_to_anchor=(1, -0.2))
# Show Plot
plt.show()
return None
Returns
-------
None
"""
self.plots.draw()

def info(self):
"""Prints and plots summarized information of the nose cone.
Expand Down Expand Up @@ -873,7 +855,15 @@ def __fin_num_correction(_, n):
return n / 2

def draw(self):
"""Draw the fin shape along with some important information, including
the center line, the quarter line and the center of pressure position.
Returns
-------
None
"""
self.plots.draw()
return None


class TrapezoidalFins(Fins):
Expand Down
70 changes: 69 additions & 1 deletion rocketpy/plots/aero_surface_plots.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,75 @@ def __init__(self, nosecone):
return None

def draw(self):
# This will de done in the future
"""Draw the nosecone shape along with some important information,
including the center line and the center of pressure position.
Returns
-------
None
"""
self.aero_surface.evaluate_nose_shape()
# Figure creation and set up
fig_ogive, ax = plt.subplots()
ax.set_xlim(-0.05, self.aero_surface.length * 1.02) # Horizontal size
ax.set_ylim(
-self.aero_surface.base_radius * 1.05, self.aero_surface.base_radius * 1.05
) # Vertical size
ax.set_aspect("equal") # Makes the graduation be the same on both axis
ax.set_facecolor("#EEEEEE") # Background color
ax.grid(True, linestyle="--", linewidth=0.5)

cp_plot = (self.aero_surface.cpz, 0)
# Plotting
ax.plot(
self.aero_surface.nosecone_x,
self.aero_surface.nosecone_y,
linestyle="-",
color="#A60628",
) # Ogive's upper side
ax.plot(
self.aero_surface.nosecone_x,
-self.aero_surface.nosecone_y,
linestyle="-",
color="#A60628",
) # Ogive's lower side
ax.scatter(
*cp_plot, label="Center Of Pressure", color="red", s=100, zorder=10
) # Center of pressure inner circle
ax.scatter(
*cp_plot, facecolors="none", edgecolors="red", s=500, zorder=10
) # Center of pressure outer circle
# Center Line
ax.plot(
[0, self.aero_surface.nosecone_x[len(self.aero_surface.nosecone_x) - 1]],
[0, 0],
linestyle="--",
color="#7A68A6",
linewidth=1.5,
label="Center Line",
)
# Vertical base line
ax.plot(
[
self.aero_surface.nosecone_x[len(self.aero_surface.nosecone_x) - 1],
self.aero_surface.nosecone_x[len(self.aero_surface.nosecone_x) - 1],
],
[
self.aero_surface.nosecone_y[len(self.aero_surface.nosecone_y) - 1],
-self.aero_surface.nosecone_y[len(self.aero_surface.nosecone_y) - 1],
],
linestyle="-",
color="#A60628",
linewidth=1.5,
)

# Labels and legend
ax.set_xlabel("Length")
ax.set_ylabel("Radius")
ax.set_title(self.aero_surface.kind + " Nose Cone")
ax.legend(bbox_to_anchor=(1, -0.2))
# Show Plot
plt.show()
return None


Expand Down

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