%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % How to evaluate wind chill formula in Matlab % Approach 1: Set variables T and V, then evaluate formula T = 45 T = 45 V = 10 V = 10 WCF = 35.7 + 0.6*T - 35.7*V^0.16 + 0.43*T*V^0.16 WCF = 39.0671 % Approach 2: evaluate formula with embedded values of T,V WCF = 35.7 + 0.6*45- 35.7*10^0.16 + 0.43*45*10^0.16 WCF = 39.0671 % Approach 1 is better because you can easily modify T,V, e.g. T=45; V=0; WCF = 35.7 + 0.6*T - 35.7*V^0.16 + 0.43*T*V^0.16 WCF = 62.7000 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Random numbers % The rand function produces a random real number between 0 and 1 rand ans = 0.9649 % So 20*rand produces a random real number between 0 and 20 20*rand ans = 3.1523 20*rand ans = 19.4119 % and 20 + 30*rand produces and random real between 20 and 50 20+30*rand ans = 42.7322 20+30*rand ans = 31.7668 20+30*rand ans = 20.9550 % randi(N) produces a random integer between 1 and N randi(4) ans = 3 randi(4) ans = 1 % so 100 + randi(10) 100 + randi(11) % gives rnadom numbers btwn 101 and 110 ans = 107 100 + randi(11) % gives rnadom numbers btwn 101 and 111 ans = 106 % round(10*rand) will produce random integers between 0 and 10, % but it's not as efficient as using the randi() function round(10*rand) ans = 8 round(10*rand) ans = 4 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Boolean expressions, also known as logical expressions % double equals signs means evaluate whether both sides are equal % return true or false accordingly 3 == 2 + 1 % remember 1 == true ; 0 == false ans = 1 3 == 2 - 1 % remember 1 == true ; 0 == false ans = 0 % here (3 == 2) evaluates to 0, which is then added to 1 (3 == 2) + 1 ans = 1 % variables b and c are undefined b > c + 1 Undefined function or variable 'b'. % but 'b' is the character b 'b' ans = b 'c' ans = c class('b') ans = char % cast char 'b' to an integer uint32 uint32('b') ans = 98 % cast char 'c' to an integer uint32('c') ans = 99 % to evaluate this expression, Matlab casts 'b' and 'c' to their % integer values and then evaluates the integer equation 'b' >= 'c' + 1 ans = 0 'b' >= 'c' - 1 ans = 1