Learn Encapsulation by Building a Projectile Trajectory Calculator - Step 21

Tell us what’s happening:

i got the same result as instructed but sill not their what am i doing wrong ?

Your code so far

import math

GRAVITATIONAL_ACCELERATION = 9.81
PROJECTILE = "∙"
x_axis_tick = "T"
y_axis_tick = "⊣"

class Projectile:
    __slots__ = ('__speed', '__height', '__angle')

    def __init__(self, speed, height, angle):
        self.__speed = speed
        self.__height = height
        self.__angle = math.radians(angle)
        
    def __str__(self):
        return f'''
Projectile details:
speed: {self.speed} m/s
height: {self.height} m
angle: {self.angle}°
displacement: {round(self.__calculate_displacement(), 1)} m
'''

    def __calculate_displacement(self):
        horizontal_component = self.__speed * math.cos(self.__angle)
        vertical_component = self.__speed * math.sin(self.__angle)
        squared_component = vertical_component**2
        gh_component = 2 * GRAVITATIONAL_ACCELERATION * self.__height
        sqrt_component = math.sqrt(squared_component + gh_component)
        
        return horizontal_component * (vertical_component + sqrt_component) / GRAVITATIONAL_ACCELERATION
        
    def __calculate_y_coordinate(self, x):
        height_component = self.__height
        angle_component = math.tan(self.__angle) * x
        acceleration_component = GRAVITATIONAL_ACCELERATION * x ** 2 / (
                2 * self.__speed ** 2 * math.cos(self.__angle) ** 2)
        y_coordinate = height_component + angle_component - acceleration_component

        return y_coordinate
    
    def calculate_all_coordinates(self):
        return [
            (x, self.__calculate_y_coordinate(x))
            for x in range(math.ceil(self.__calculate_displacement()))
        ]

    @property
    def height(self):
        return self.__height

    @property
    def angle(self):
        return round(math.degrees(self.__angle))

    @property
    def speed(self):
        return self.__speed

    @height.setter
    def height(self, n):
        self.__height = n

    @angle.setter
    def angle(self, n):
        self.__angle = math.radians(n)

    @speed.setter
    def speed(self, s):
       self.__speed = s
    
    def __repr__(self):
        return f'{self.__class__}({self.speed}, {self.height}, {self.angle})'

class Graph:
    __slots__ = ('__coordinates')

    def __init__(self, coord):
        self.__coordinates = coord

    def __repr__(self):
        return f"Graph({self.__coordinates})"

    def create_coordinates_table(self):
        table = '\n  x      y\n'
        for x, y in self.__coordinates:
            table += f'{x:>3}{y:>7.2f}\n'

        return table


# User Editable Region

    
    def create_trajectory(self):          
        rounded_coords = [(round(x), round(y)) for x, y in self.__coordinates]
        x_max = max(rounded_coords, key=lambda i: i[0])[0]
        y_max = max(rounded_coords, key=lambda j: j[1])[1] 
        trajectory_grid = [[" " for _ in range(x_max + 1)] for _ in range(y_max + 1)]  
        for x, y in rounded_coords:
            trajectory_grid[-1 - y][x] = PROJECTILE  
        for row in range(len(trajectory_grid)):
            trajectory_grid[row] = [y_axis_tick] + trajectory_grid[row]   
        x_axis_line = [" "] + [x_axis_tick] * (x_max + 1)
        trajectory_grid.append(x_axis_line)    
        trajectory_chart = ['"' + "".join(row) + '",' for row in trajectory_grid]
        return  trajectory_chart       

# User Editable Region


ball = Projectile(10, 3, 45)
print(ball)
coordinates = ball.calculate_all_coordinates()
graph = Graph(coordinates)
for row in graph.create_trajectory():
    print(row) 
   

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Challenge Information:

Learn Encapsulation by Building a Projectile Trajectory Calculator - Step 21

The “Example code” section is a bit mis-leading here. Your output should look like this:

⊣     ∙       
⊣  ∙∙∙ ∙∙∙    
⊣ ∙       ∙   
⊣∙         ∙  
⊣           ∙ 
⊣            ∙
⊣             
 TTTTTTTTTTTTT

You should output a string, not a list.

1 Like

Thanks a lot for the help. i was at this for hours and more

1 Like

I guess technically here the returned list is as described in the example…but the final output is different.

If you have added a print here:

        print(trajectory_chart)
        return  trajectory_chart 

You could see the extra quotes and commas in your array:

['"⊣     ∙       ",',
 '"⊣  ∙∙∙ ∙∙∙    ",',
 '"⊣ ∙       ∙   ",',
 '"⊣∙         ∙  ",',
 '"⊣           ∙ ",',
 '"⊣            ∙",',
 '"⊣             ",',
 '" TTTTTTTTTTTTT",'
]

You added them to match the example :+1: