changes in Notebooks

Author: Nicolas Tremblay

mini_test.ipynb

@@ -27,7 +27,9 @@
  "import scipy\n",
  "import pygsp\n",
  "from matplotlib import pyplot as plt\n",
- "import pandas as pd"
+ "import pandas as pd\n",
+ "import sklearn\n",
+ "import networkx as nx"
  ]
  },
  {

notebooks/02_spectral.ipynb

@@ -165,3 +165,23 @@ def AR_index(c1,c2):
 
 
  return res
+
+def generate_concentric_circles(N_in, N_out, sigma_in, sigma_out):
+ '''
+ Create a simple data set made of two concentric distributions
+ data, truth = generate_concentric_circles(N_in, N_out, sigma_in, sigma_out)
+ '''
+ data = np.empty((N_in+N_out,2)) * np.nan
+ # first cluster
+ x = 2*np.random.rand(1,N_out)-1;
+ y = 2*np.random.rand(1,N_out)-1;
+ data[:N_out,0] = x / np.sqrt(x**2 + y**2) + sigma_out * np.random.randn(1,N_out)
+ data[:N_out,1] = y / np.sqrt(x**2 + y**2) + sigma_out * np.random.randn(1,N_out)
+
+ # second cluster
+ data[N_out:,0] = sigma_in * np.random.randn(1, N_in)
+ data[N_out:,1] = sigma_in * np.random.randn(1, N_in)
+
+ truth = np.zeros((N_in+N_out,))
+ truth[N_out:]=1
+ return data, truth