code: def dirichlet_eval(w, alpha):
      """
      Evaluate the probability of a certain discrete draw w
      from the Dirichlet density with parameters alpha
  
      Parameters
      ----------
      w: array of shape (n)
      alpha: array of shape (n)
      """
      if np.shape(w) != np.shape(alpha):
          raise ValueError("incompatible dimensions")
      loge = np.sum((alpha - 1) * np.log(w))
      logb = np.sum(gammaln(alpha)) - gammaln(alpha.sum())
      loge -= logb
      return np.exp(loge)
  
imports: import math
  import numpy
  import numpy.random
  from scipy.linalg import cholesky, eigvalsh, inv
  from scipy.special import gammaln
  from .gmm import GMM
  from .utils import kmeans
label_desc: Use image node_id 2 for calling a global function with example usage: dirichlet_eval(w, alpha) and returns: np