This screencast is about the programming implementation of Trapezoidal rule, which is an algorithm of numerical integration. The screencast was recorded during a class session. The demonstration also includes development of a user-defined function for trapezoidal rule which takes the integrand function "f(x)", integration limits "a" and "b", and number of subintervals "h" as its arguments. The programming concepts to be noted are;
1-Like any other fortran's user-defined function, this function can be stored in a separate file and integrated with other programs.
2- The integrand function/s must the declared in the main program with the key word "external" to represent their context of being used as argument in a user-defined function.
