debut tp

tp4/MethodeGaussPivotPartiel.py

 import math
 import numpy as np
 import matplotlib.pyplot as plt
+from scipy.linalg import lu
 
-A=np.array([[1.,2.,3.],[0.,1.,2.],[0.,0.,1.]])
-B=np.array([14.,8.,3.])
-C=np.array([[1.,0.,0.],[1.,2.,0.],[1.,2.,1.]])
+A = np.array([[1.,2.,3.],[0.,1.,2.],[0.,0.,1.]],dtype=np.float64)
+B = np.array([15.,20.,8.])
+C = np.array([[1.,0.,0.],[1.,2.,0.],[1.,2.,1.]],dtype=np.float64)
+D = np.array([[1.,1.,4.],[1.,2.,5.],[1.,2.,1.]],dtype=np.float64)
 
 
 def ResolutionRemontee(A,B):
@@ -12,7 +14,7 @@ def ResolutionRemontee(A,B):
     for i in range(0,n):
         if (A[i,i] == 0):
             return 0;
-    X=np.empty([n,1],dtype = np.float64)
+    X = np.empty([n],dtype = np.float64)
     X[n-1] = B[n-1]/A[n-1][n-1]
 
     for i in range(n-1,-1,-1):
@@ -28,7 +30,7 @@ def ResolutionDescente(C,B):
     for i in range(0,n):
         if (C[i,i] == 0):
             return 0;
-    X=np.empty([n,1],dtype = np.float64)
+    X = np.empty([n],dtype = np.float64)
     X[1] = B[1]/C[1][1]
 
     for i in range(0,n):
@@ -39,5 +41,35 @@ def ResolutionDescente(C,B):
 
 
 def GaussPivotPartiel(A,B):
-    I=np.array([[1,0,0],[0,1,0],[0,0,1]])
+    n = A.shape[0]
+    for i in range(0,n-1):
+        l = i
+        for k in range(i,n):
+            if(abs(A[k][i])>abs(A[l][i])):
+                l = k
+
+        if (l != i):
+            for j in range(i,n+1):
+                tmp = A[l][j]
+                A[l][j] = A[i][j]
+                A[i][j] = tmp
+            tmp = B[l]
+            B[l] = B[i]
+            B[i] = tmp
+
+        pivot = A[i][i]
+        for k in range(i+1,n):
+            factpivot = A[k][i]/pivot
+            A[k][i] = 0
+            for j in range(i+1,n):
+                A[k][j] = A[k][j] - factpivot*A[i][j]
+            B[k] =  B[k] - factpivot * B[i]
+    return ResolutionRemontee(A,B)
+
+
+print(GaussPivotPartiel(D,B))
+
+
+
+