1 files changed, 51 insertions, 0 deletions
diff --git a/lj_matrix/frob_norm.py b/lj_matrix/frob_norm.py
new file mode 100644
index 000000000..4c3a2945d
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+++ b/lj_matrix/frob_norm.py
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+"""MIT License
+
+Copyright (c) 2019 David Luevano Alvarado
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+"""
+import math
+
+
+def frob_norm(array):
+    """
+    Calculates the frobenius norm of a given array or matrix.
+    array: array of data.
+    """
+
+    arr_sh_len = len(array.shape)
+    arr_range = range(len(array))
+    fn = 0.0
+
+    # If it is a 'vector'.
+    if arr_sh_len == 1:
+        for i in arr_range:
+            fn += array[i]*array[i]
+
+        return math.sqrt(fn)
+
+    # If it is a matrix.
+    elif arr_sh_len == 2:
+        for i in arr_range:
+            for j in arr_range:
+                fn += array[i, j]*array[i, j]
+
+        return math.sqrt(fn)
+    else:
+        print('Error. Array size greater than 2 ({}).'.format(arr_sh_len))