Comment migration

Most comments from cpp are migrated here to the header.

random_price.h

@@ -1,17 +1,21 @@
 #ifndef RANDOM_PRICE_H
 #define RANDOM_PRICE_H
+
 /**
 #ifndef 
 #define are to prevent double include the header
 */
 /**
 * Initial Stock Price Generator
-* if a=1 mean 5 sd 2; if a=2 mean 50 sd 20; if a=3 mean 150 sd 50;
+* if a=2 mean 50 sd 20; if a=3 mean 150 sd 50; else mean 5 sd 2;
+*Stock prices cluster in 3 tiers in our world: about 5 hkd (a=ELSE) variating about 2 hkd; , 50 hkd(a=2) variating about 20 hkd, 
+*and 150 hkd(a=3)variating about 50 hkd (based on a very little sample observation of real world). 
 */
 double init_stock_price(int a);
 /**
 * Stock Standard Deviation Generator (for both initial and after initial)
-* mean 0.03*init_price; s.d. 0.02*init_price (yes, s.d. of s.d.)
+* s.d. usually 1%-5% of initial stock price; 
+* modelling with absolute value of norm dist mean 0.03*init_price; s.d. 0.02*init_price (yes, s.d. of s.d.)
 */
 double random_sd(float init_price);
 /**
@@ -22,6 +26,7 @@ double random_sd(float init_price);
 double random_stock(float &mean, float &sd,float &upper_limit, float &lower_limit);
 /**
 * Random integer function in choosing stock type
+* Return a random integer from 0 to max - 1
 */
 unsigned int random_integer(unsigned int max_integer);
 #endif