2020-10-19 21:08:55

This commit is contained in:
wizardforcel
2020-10-19 21:08:55 +08:00
parent 7f63048035
commit ab0caba1f0
140 changed files with 3982 additions and 3982 deletions

View File

@@ -23,7 +23,7 @@
In [1]:
```
```py
from scipy.sparse import *
import numpy as np
@@ -33,14 +33,14 @@ import numpy as np
In [2]:
```
```py
coo_matrix((2,3))
```
Out[2]:
```
```py
<2x3 sparse matrix of type '<type 'numpy.float64'>'
with 0 stored elements in COOrdinate format>
```
@@ -49,13 +49,13 @@ Out[2]:
In [3]:
```
```py
A = coo_matrix([[1,2,0],[0,0,3],[4,0,5]])
print A
```
```
```py
(0, 0) 1
(0, 1) 2
(1, 2) 3
@@ -68,20 +68,20 @@ print A
In [4]:
```
```py
type(A)
```
Out[4]:
```
```py
scipy.sparse.coo.coo_matrix
```
In [5]:
```
```py
B = A.tocsr()
type(B)
@@ -89,7 +89,7 @@ type(B)
Out[5]:
```
```py
scipy.sparse.csr.csr_matrix
```
@@ -97,7 +97,7 @@ scipy.sparse.csr.csr_matrix
In [6]:
```
```py
C = A.todense()
C
@@ -105,7 +105,7 @@ C
Out[6]:
```
```py
matrix([[1, 2, 0],
[0, 0, 3],
[4, 0, 5]])
@@ -115,7 +115,7 @@ matrix([[1, 2, 0],
In [7]:
```
```py
v = np.array([1,0,-1])
A.dot(v)
@@ -123,7 +123,7 @@ A.dot(v)
Out[7]:
```
```py
array([ 1, -3, -1])
```
@@ -131,7 +131,7 @@ array([ 1, -3, -1])
In [8]:
```
```py
I = np.array([0,3,1,0])
J = np.array([0,3,1,2])
V = np.array([4,5,7,9])
@@ -141,12 +141,12 @@ A = coo_matrix((V,(I,J)),shape=(4,4))
In [9]:
```
```py
print A
```
```
```py
(0, 0) 4
(3, 3) 5
(1, 1) 7
@@ -158,7 +158,7 @@ COO 格式的稀疏矩阵在构建的时候只是简单的将坐标和值加到
In [10]:
```
```py
I = np.array([0,0,1,3,1,0,0])
J = np.array([0,2,1,3,1,0,0])
V = np.array([1,1,1,1,1,1,1])
@@ -167,7 +167,7 @@ print B
```
```
```py
(0, 0) 1
(0, 2) 1
(1, 1) 1
@@ -182,13 +182,13 @@ print B
In [11]:
```
```py
C = B.tocsr()
print C
```
```
```py
(0, 0) 3
(0, 2) 1
(1, 1) 2
@@ -200,7 +200,7 @@ print C
In [12]:
```
```py
from scipy.sparse import lil_matrix
from scipy.sparse.linalg import spsolve
from numpy.linalg import solve, norm
@@ -212,7 +212,7 @@ from numpy.random import rand
In [13]:
```
```py
A = lil_matrix((1000, 1000))
A[0, :100] = rand(100)
A[1, 100:200] = A[0, :100]
@@ -224,7 +224,7 @@ A.setdiag(rand(1000))
In [14]:
```
```py
A = A.tocsr()
b = rand(1000)
x = spsolve(A, b)
@@ -235,7 +235,7 @@ x = spsolve(A, b)
In [15]:
```
```py
x_ = solve(A.toarray(), b)
```
@@ -244,7 +244,7 @@ x_ = solve(A.toarray(), b)
In [16]:
```
```py
err = norm(x-x_)
err
@@ -252,7 +252,7 @@ err
Out[16]:
```
```py
6.4310987107687431e-13
```
@@ -262,7 +262,7 @@ Out[16]:
In [17]:
```
```py
from scipy import sparse
row, col, val = sparse.find(C)
@@ -270,7 +270,7 @@ print row, col, val
```
```
```py
[0 0 1 3] [0 2 1 3] [3 1 2 1]
```
@@ -281,14 +281,14 @@ print row, col, val
In [18]:
```
```py
sparse.issparse(B)
```
Out[18]:
```
```py
True
```
@@ -296,14 +296,14 @@ True
In [19]:
```
```py
sparse.isspmatrix(B.todense())
```
Out[19]:
```
```py
False
```
@@ -311,26 +311,26 @@ False
In [20]:
```
```py
sparse.isspmatrix_coo(B)
```
Out[20]:
```
```py
True
```
In [21]:
```
```py
sparse.isspmatrix_csr(B)
```
Out[21]:
```
```py
False
```