import?numpy?as?np
from?sklearn?import?linear_model
import?scipy.misc
from?PIL?import?Image
from?matplotlib?import?pyplot?as?plt
from?time?import?time


class?KSVD（object）:
????def?__init__（self?n_components?max_iter=50?tol=1e-6
?????????????????n_nonzero_coefs=None）:
????????“““
????????稀疏模型Y?=?DX，Y為樣本矩陣，使用KSVD動態(tài)更新字典矩陣D和稀疏矩陣X
????????:param?n_components:?字典所含原子個數(shù)（字典的列數(shù)）
????????:param?max_iter:?最大迭代次數(shù)
????????:param?tol:?稀疏表示結(jié)果的容差
????????:param?n_nonzero_coefs:?稀疏度
????????“““
????????self.dictionary?=?None
????????self.sparsecode?=?None
????????self.max_iter?=?max_iter
????????self.tol?=?tol
????????self.n_components?=?n_components
????????self.n_nonzero_coefs?=?n_nonzero_coefs

????#def?_initialize（self?y）:
????????“““
????????初始化字典矩陣
????????“““
???????#?u?s?v?=?np.linalg.svd（y）
????????#self.dictionary?=?u[:?:self.n_components]

????def?_update_dict（self?y?d?x）:
????????“““
????????使用KSVD更新字典的過程
????????“““
????????for?i?in?range（self.n_components）:
????????????index?=?np.nonzero（x[i?:]）[0]
????????????if?len（index）?==?0:
????????????????continue

????????????d[:?i]?=?0
????????????r?=?（y?-?np.dot（d?x））[:?index]
????????????u?s?v?=?np.linalg.svd（r?full_matrices=False）
????????????d[:?i]?=?u[:?0].T
????????????x[i?index]?=?s[0]?*?v[0?:]
????????print?（d[3?:]）
????????print?（“_____“）
????????print?（x[i?:]）
???