add a derivation function in python

c_programs/test_global_local_variables.c

@@ -2,25 +2,26 @@
 
 unsigned char l[3] = {1, 2, 3};
 
-void g() {
-    printf("outside g: l: %d, %d, %d\n", l[0], l[1], l[2]);
+void g0() {
+    printf("g0: outside l: %d, %d, %d\n", l[0], l[1], l[2]);
+    unsigned char l[3] = {2, 3, 4};
     void g1() {
-        printf("outside g1: l: %d, %d, %d\n", l[0], l[1], l[2]);
-        unsigned char l[3] = {2, 3, 4};
+        printf("g1: outside l: %d, %d, %d\n", l[0], l[1], l[2]);
+        unsigned char l[3] = {3, 4, 6};
         void g2() {
-            printf("outside g2: l: %d, %d, %d\n", l[0], l[1], l[2]);
-            unsigned char l[3] = {3, 4, 5};
-            printf("inside g2: l: %d, %d, %d\n", l[0], l[1], l[2]);
+            printf("g2: outside l: %d, %d, %d\n", l[0], l[1], l[2]);
+            unsigned char l[3] = {4, 5, 8};
+            printf("g2:  inside l: %d, %d, %d\n", l[0], l[1], l[2]);
         }
         g2();
-        printf("inside g1: l: %d, %d, %d\n", l[0], l[1], l[2]);
+        printf("g1:  inside l: %d, %d, %d\n", l[0], l[1], l[2]);
     }
     g1();
-    printf("inside g: l: %d, %d, %d\n", l[0], l[1], l[2]);
+    printf("g0:  inside l: %d, %d, %d\n", l[0], l[1], l[2]);
 }
 
 int main(int argc, char* argv[]) {
-    g();
+    g0();
 
     return 0;
 }

picture_manipulation/picture_derivations.py

@@ -0,0 +1,61 @@
+#! /usr/bin/python3.5
+
+import numpy as np
+
+from PIL import Image
+
+def padding_one_pixel(pix):
+    shape = pix
+    pix_1 = np.vstack((pix[0], pix, pix[-1])).T
+    pix_2 = np.vstack((pix_1[0], pix_1, pix_1[-1])).T
+    return pix_2
+
+shape = (5, 6)
+pix = np.random.randint(0, 10, shape)
+
+print("pix:\n{}".format(pix))
+
+part = pix[0:3, 0:3]
+print("part:\n{}".format(part))
+
+pix_pad = padding_one_pixel(pix)
+print("pix_pad:\n{}".format(pix_pad))
+
+idx_y, idx_x = np.array([(j, i) for j in range(0, 3) for i in range(0, 3)]).T
+
+idx_y_row = np.zeros((0, 9)).astype(np.int)
+idx_x_row = np.zeros((0, 9)).astype(np.int)
+for j in range(0, shape[0]):
+    for i in range(0, shape[1]):
+        idx_y_row = np.vstack((idx_y_row, idx_y+j))
+        idx_x_row = np.vstack((idx_x_row, idx_x+i))
+
+idx_y_row = idx_y_row.reshape((-1, ))
+idx_x_row = idx_x_row.reshape((-1, ))
+
+print("idx_y: {}".format(idx_y))
+print("idx_x: {}".format(idx_x))
+print("idx_y_row:\n{}".format(idx_y_row))
+print("idx_x_row:\n{}".format(idx_x_row))
+print("pix_pad[idx_y, idx_x]: {}".format(pix_pad[idx_y, idx_x]))
+print("pix_pad[idx_y_row, idx_x_row]:\n{}".format(pix_pad[idx_y_row, idx_x_row]))
+pix_deriv_table = pix_pad[idx_y_row, idx_x_row].reshape(shape[0]*shape[1], 3*3)
+print("pix_deriv_table:\n{}".format(pix_deriv_table))
+
+mask_sobel = np.zeros((3, 3)).astype(np.int)
+mask_sobel[0] = -1
+mask_sobel[2] = 1
+mask_x = mask_sobel.copy().reshape((-1, ))
+mask_y = mask_sobel.T.copy().reshape((-1, ))
+
+print("mask_x: {}".format(mask_x))
+print("mask_y: {}".format(mask_y))
+
+pix_deriv_x = np.sum(pix_deriv_table*mask_x, axis=1).reshape(shape)
+pix_deriv_y = np.sum(pix_deriv_table*mask_y, axis=1).reshape(shape)
+
+print("pix_deriv_x: {}".format(pix_deriv_x))
+print("pix_deriv_y: {}".format(pix_deriv_y))
+
+if __name__ == "__main__":
+    print("Hello World!")

test_programs/test_global_local_variables.py

@@ -0,0 +1,26 @@
+#! /usr/bin/python3.5
+
+# -*- coding: utf-8 -*-
+
+l = [1, 2, 3]
+# globals()["l"] = [1, 2, 3]
+def g0():
+    global l
+    print("g0: outside l: {}".format(l))
+    l = [2, 3, 4]
+    def g1():
+        global l
+        print("g1: outside l: {}".format(l))
+        l = [3, 4, 6]
+        def g2():
+            global l
+            print("g2: outside l: {}".format(l))
+            l = [4, 5, 8]
+            print("g2: inside  l: {}".format(l))
+        g2()
+        print("g1: inside  l: {}".format(l))
+    g1()
+    print("g0: inside  l: {}".format(l))
+
+if __name__ == "__main__":
+    g0()