tasks a-s

Task/Reduced-row-echelon-form/Python/reduced-row-echelon-form.py

@@ -0,0 +1,35 @@
+def ToReducedRowEchelonForm( M):
+    if not M: return
+    lead = 0
+    rowCount = len(M)
+    columnCount = len(M[0])
+    for r in range(rowCount):
+        if lead >= columnCount:
+            return
+        i = r
+        while M[i][lead] == 0:
+            i += 1
+            if i == rowCount:
+                i = r
+                lead += 1
+                if columnCount == lead:
+                    return
+        M[i],M[r] = M[r],M[i]
+        lv = M[r][lead]
+        M[r] = [ mrx / lv for mrx in M[r]]
+        for i in range(rowCount):
+            if i != r:
+                lv = M[i][lead]
+                M[i] = [ iv - lv*rv for rv,iv in zip(M[r],M[i])]
+        lead += 1
+
+
+mtx = [
+   [ 1, 2, -1, -4],
+   [ 2, 3, -1, -11],
+   [-2, 0, -3, 22],]
+
+ToReducedRowEchelonForm( mtx )
+
+for rw in mtx:
+  print ', '.join( (str(rv) for rv in rw) )