Added documentation for tutorial

01_IntroductionToPython/Tutorial/README.md

+## 01 Tutorial: Introduction to Python
+
+The task for this tutorial can be found in the [01_Tutorial_PythonIntroduction jupyter notebook](01_Tutorial_PythonIntroduction.ipynb). Following, the steps how to import the jupyter notebook to [jupyter hub](https://jupyter.rwth-aachen.de/hub/login).
+
+1. Download the [01_Tutorial_PythonIntroduction jupyter notebook](https://git.rwth-aachen.de/introduction-to-robotics-course/introduction-to-robotics-2023/-/blob/main/01_IntroductionToPython/01_Tutorial_PythonIntroduction.ipynb).
+
+    ![GIF that shows download of the jupyter notebook](media/download_jupyter_notebook.gif)
+
+2. Open the [RWTH JupyterHub](https://jupyter.rwth-aachen.de/hub/login) website and sign in using RWTH Single Sign-On.
+
+    ![GIF showing sign in process to RWTH jupyterHub](media/login_jupyterHub.gif)
+
+3. Inside RWTH JupyterHub create a new folder named **i2r**.
+
+    ![GIF showing process to create new folder](media/creating_folder.gif)
+
+4. Upload the [01_Tutorial_PythonIntroduction jupyter notebook](01_Tutorial_PythonIntroduction.ipynb) and the [forward_kinematics module](forward_kinematics.py) to the **i2r** folder.
+
+    ![GIF showing process to import files](media/import_files.gif)
+
+5. You can open the file by just double-click the file name in the file browser.
+
+    ![GIF showing how to open files](media/opening_files.gif)
+
+6. To run/execute the code you implemented in a cell, click into that cell and click the ***Run the selected cells and advance*** button like show below.
+
+    ![GIF showing how to run a cell](media/run_a_cell.gif)
+
+7. Once you made changes inside the file **forward_kinematics.py** make sure to save the file (Press `Ctrl` + `S` (on a german keyboard `Strg` + `S`)) and click on ***Restart the kernal, then re-run the whole notebook*** inside of the notebook from which you are calling a function of the module.
+
+    ![GIF showing how to restart the kernal](media/restart_kernal.gif)
+

01_IntroductionToPython/Tutorial/forward_kinematics.py

+# This Python file contains different functions we implemented to perform forward kinematics
+# 
+# First we have to make sure to import the modules with the functions we need for the functions.
+# Here we just need the 'math' module which includes among others the following functions:
+# - cos(x): returns cosine of x in radians
+# - sin(x): returns sine of x in radians
+# - radians(x): converts x from degree to radians
+
+import math
+
+# Here we define the function of the name 'forward_kinematics_nLinks_2'.
+# For an elbow manipulator in planar space with 2 DoF the function calculates 
+# the coordinates of the end effector joint.
+# The function has to be called with the follwing arguments:
+# - a_1: length of link 1
+# - a_2: lenght of link 2
+# - theta_1: rotation of joint 1
+# - theta_2: rotation of joint 2
+# The function returns the x and y coordinate of the end effector joint.
+def forward_kinematics_nLinks_2(a_1, a_2, theta_1, theta_2):
+    
+    x = a_1 * math.cos(math.radians(theta_1)) + a_2 * math.cos(math.radians(theta_1 + theta_2))
+    y = a_1 * math.sin(math.radians(theta_1)) + a_2 * math.sin(math.radians(theta_1 + theta_2))
+    
+    return x, y
+
+# Here we define the function of the name 'forward_kinematics'.
+# For an elbow manipulator in planar space with n DoF the function calculates 
+# the coordinates of the end effector joint.
+# The function has to be called with the follwing arguments:
+# - x_0: x coordinate of the refernce coordinate frame
+# - y_0: y coordinate of the reference coordinate frame
+# - list_a: list with the lenghts [a_1, a_2, ..., a_n] of the links
+# - list_theta: list with the rotations [theta_1, theta_2, ..., theta_n] of the joints
+# The function returns the x and y coordinate of the end effector joint.
+def forward_kinematics(x_0, y_0, list_a, list_theta):
+    x = x_0
+    y = y_0
+    sum_theta = 0
+    # The zip() function takes iterables (can be zero or more), aggregates them in a tuple, and returns it.
+    for a, theta in zip(list_a, list_theta): 
+        sum_theta = sum_theta + theta
+        x = x + a * math.cos(math.radians(sum_theta))
+        y = y + a * math.sin(math.radians(sum_theta))
+        
+    return x, y
+
+
+# Here we define the function of the name 'fk_getJointCoords'.
+# For an elbow manipulator in planar space with n DoF the function calculates 
+# the coordinates of the joints.
+# The function has to be called with the follwing arguments:
+# - x_0: x coordinate of the refernce coordinate frame
+# - y_0: y coordinate of the reference coordinate frame
+# - list_a: list with the lenghts [a_1, a_2, ..., a_n] of the links
+# - list_theta: list with the rotations [theta_1, theta_2, ..., theta_n] of the joints
+# The function returns two lists. 'joint_x_coords' contains the x coordinates of the joints and
+# 'joint_y_coords' contains the y coordinates of the joints.
+# This function is used to be able to plot the resulting elbow manipulator configuration.
+def fk_getJointCoords(x_0, y_0, list_a, list_theta):
+    x = x_0
+    y = y_0
+    sum_theta = 0
+    
+    joint_x_coords = [x_0]
+    joint_y_coords = [y_0]
+    
+    # The zip() function takes iterables (can be zero or more), aggregates them in a tuple, and returns it.
+    for a, theta in zip(list_a, list_theta): 
+        sum_theta = sum_theta + theta
+        x = x + a * math.cos(math.radians(sum_theta))
+        y = y + a * math.sin(math.radians(sum_theta))
+        joint_x_coords.append(x)
+        joint_y_coords.append(y)
+    
+    return joint_x_coords, joint_y_coords
+    
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