# -*- coding: utf-8 -*- """ Demo script to go along with a Python tutorial @ BIG (EPFL). http://naereen.github.io/slides/2016_07__Python_demo_at_EPFL/ - Author: Lilian Besson - Date: 07 July 2016 - License: MIT License (http://lbesson.mit-license.org/) - GitHub: http://naereen.github.io/slides/2016_07__Python_demo_at_EPFL/ """ # %% First example print("Hello Python world!") # Hello Python world! # %% Graphical example 1 import numpy as np import matplotlib.pyplot as plt t = np.linspace(0, 2 * np.pi, 400) x = np.cos(2*t) y = np.cos(3*t) plt.figure() plt.plot(x, y, 'r+-') plt.show() # %% Graphical example 2 from scipy.special import gamma x = np.linspace(0.1, 3, 400) y = gamma(x) plt.figure() plt.plot(x, y) plt.title("The function $\Gamma(x)$ on $[0.1, 3]$") plt.show() # %% Reading an image from scipy import ndimage # module for n-d images import matplotlib.pyplot as plt # module for plotting from scipy import misc # some toy data are in this module face = misc.face() # Or... # face = plt.imread('face.png') # Or... from skimage.io import imread # import a function # face = imread('face.jpg') print(face[0, 0]) # first pixel: 114 # display the image plt.imshow(face, cmap='gray') plt.show() # %% More on images lx, ly = face.shape # cropping, by slicing the ndarray (matrix) crop_face = face[lx / 4: - lx / 4, ly / 4: - ly / 4] # up <-> down flip flip_ud_face = np.flipud(face) # rotation rotate_face = ndimage.rotate(face, 45) rotate_face_noreshape = ndimage.rotate(face, 45, reshape=False) plt.figure() plt.subplot(2, 3, 1) plt.imshow(face, cmap='gray') plt.subplot(2, 3, 2) plt.imshow(crop_face, cmap='gray') plt.subplot(2, 3, 3) plt.imshow(flip_ud_face, cmap='gray') plt.subplot(2, 3, 4) plt.imshow(rotate_face, cmap='gray') plt.subplot(2, 3, 5) plt.imshow(rotate_face_noreshape, cmap='gray')