Fibonacci

This tutorial looks towards creating an AR visualisation of the fibonacci sequence with arrays using ARgorithm. It is advised you go through the previous tutorial to understand this better.

Writing the code

The Fibonacci sequence is a very popular beginner’s problem to explain the concepts of recursion and dynamic programming. In this example, we will be implementing an iterative approach. The ARgorithmToolkit class that we'll be using in this example is Variable.

import ARgorithmToolkit

def run(**kwargs):
    n = kwargs["n"]
    algo = ARgorithmToolkit.StateSet()
    if n <= 0:
        algo.add_comment("n has to be natural number, try again")
        return algo

    var1 = ARgorithmToolkit.Variable("first",algo,1,comments="The first fibonacci number")
    if n == 1:
        algo.add_comment("1 is the first fibonacci number")
        return algo

    var2 = ARgorithmToolkit.Variable("second",algo,1,comments="The second fibonacci number")

    for _ in range(2, n):
        temp1 = var1.value
        temp2 = var2.value
        algo.add_comment(f"adding {temp1} and {temp2} and we get next fibonacci number {temp1+temp2}")
        var1.value = temp2
        var2.value = temp1+temp2
    algo.add_comment(f"{var2.value} is the {n}th fibonacci number")
    return algo

The Variable class is a little different from the other classes and interfaces in ARgorithmToolkit. This class does not have any functionality other than to remember the states of objects of datatypes like int,float,string,bool. It is advised to use this only when you need a particular variable rendered in augmented reality that can prove helpful to understanding the code.

Warning

Be careful when reading or writing the value of the Variable class.

>>> var = ARgorithmToolkit.Variable("var",algo,1)
>>> var
Variable(1)
>>> var.value = 3
>>> var
Variable(3)
>>> var = 3
>>> var
3

Directly assigning values to the Variable object will overwrite the object and states will no longer be recorded for it.

In the Fibonacci sequence, each number is the sum of its previous two Fibonacci numbers. We'll be using two variables to store the previously generated Fibonacci.

$$F\mathbf(n) = F\mathbf(n-1) + F\mathbf(n-2)$$

import ARgorithmToolkit

def run(**kwargs):
    n = kwargs["n"]
    algo = ARgorithmToolkit.StateSet()
    if n <= 0:
        algo.add_comment("n has to be natural number, try again")
        return algo

    var1 = ARgorithmToolkit.Variable("first",algo,1,comments="The first fibonacci number")
    if n == 1:
        algo.add_comment("1 is the first fibonacci number")
        return algo

    var2 = ARgorithmToolkit.Variable("second",algo,1,comments="The second fibonacci number")

    for _ in range(2, n):
        temp1 = var1.value
        temp2 = var2.value
        algo.add_comment(f"adding {temp1} and {temp2} and we get next fibonacci number {temp1+temp2}")
        var1.value = temp2
        var2.value = temp1+temp2
    algo.add_comment(f"{var2.value} is the {n}th fibonacci number")
    return algo

Setting up the config file

For this code, we only need one parameter that is n which is the index of the number required in the sequence. We will provide the default value for n as 4. As shown in previous tutorial, you can create this using your code editor or the configure command (how to use configure)

{
    "argorithmID": "fibonacci", 
    "file": "fibonacci.py", 
    "function": "run", 
    "parameters": {
        "n" : {
            "description" : "Enter the position of number in fibonacci series",
            "type" : "INT",
            "start" : 1
        }
    }, 
    "example": {
        "n" : 4
    }, 
    "description": "Print the nth fibonacci number"

Finally, we can submit the file to the server.

$ ARgorithm submit fibonacci
[SUCCESS]: FILES FOUND
[SUCCESS]: FILES VERIFIED
[SUCCESS]: SUBMITTED