Interval package: Difference between revisions

Interval package (edit)

1,105 bytes added , 31 October 2014

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   octave:1> infsup (1, 3) <= infsup (2, 4)
   ans =  1
+=== Matrix operations ===
+Above mentioned operations can usually also be applied to interval vectors and matrices. Many operations use [http://www.gnu.org/software/octave/doc/interpreter/Vectorization-and-Faster-Code-Execution.html#Vectorization-and-Faster-Code-Execution vectorization techniques].
+The implemented interval matrix operations comprise: exact dot product, exact matrix multiplication, exact vector sums, (not-exact) matrix inversion, matrix powers and solving linear systems. As a result of missing hardware / low-level library support, these operations are quite slow compared to familiar operations in floating-point arithmetic.
+ octave:1> A = infsup ([1, 2, 3; 4, 0, 0; 0, 0, 0], [1, 2, 3; 4, 0, 6; 0, 0, 1])
+ A = 3×3 interval matrix
+    [1]   [2]      [3]
+    [4]   [0]   [0, 6]
+    [0]   [0]   [0, 1]
+ octave:2> B = inv (A)
+ B = 3×3 interval matrix
+     [0]     [.25]      [-Inf, 0]
+    [.5]   [-.125]   [-Inf, -.75]
+     [0]       [0]       [1, Inf]
+ octave:3> A * B
+ ans = 3×3 interval matrix
+    [1]   [0]   [Entire]
+    [0]   [1]   [Entire]
+    [0]   [0]   [0, Inf]
 === Error handling ===