Steps to write a programe with Examples of Programming in R Language

Steps to write a programme

• A programme is a set of instructions or commands which are written in a sequence of operations i.e., what comes first and what comes after that.

• The objective of a programme is to obtain a defined outcome based on input variables.

• The computer is instructed to perform the defined task.

• Computer is an obedient worker but it has its own language.

• We do not understand computer's language and computer does not understand our language.

• The software help us and work like an interpreter between us and computer.

• We say something in software's language and software informs it to computer.

• Computer does the task and informs back to software.

• The software translates it to our language and informs us.

• Programme in R is written as a function using function.

• Write down the objective, i.e., what we want to obtain as an outcome.

• Translate it in the language of R.

• Identify the input and output variables.

• Identify the nature of input and output, i.e., numeric string, factor, matrix etc.

• Input and output variables can be single variable, vector, matrix or even a function itself.

• The input variables are the component of function which are reported in the argument of function ( ) .

• The output of a function can also be input to another function.

• The output of an outcome can be formatted as per the need and requirement.   

Tips :

1. Loops usually slower the speed of programmes, so better is to use vectors and matrices.
2. Use # symbol to write comment to understand the syntax.
3. Use the variable names which are easy to understand.
4. Don't forget to initialize the variables.

Example 1

Input variables : x, y, n (if x and y have different number of observations, choose different numbers, say n1 and n2)

We need summation, so use sum function or alternatively computer it through vectors.