rand_walk_dir_code.py

import math
import random

class Vector:
    def __init__(self,x,y):
        self.x = x
        self.y = y
    def __add__(self,vec2):
        return Vector(self.x+vec2.x,self.y+vec2.y)
    def __neg__(self):
        return Vector(-self.x,-self.y)
    def __sub__(self,vec2):
        return self + (-vec2)
    def __mul__(self,scalar):
        return Vector(self.x*scalar,self.y*scalar)
    def direction(self):
        return math.atan2(self.y,self.x)
    def length(self):
        return math.sqrt(self.x*self.x + self.y*self.y)
    def __str__(self):
        return "("+str(self.x)+","+str(self.y)+")"

def to_xy(dir,length):
    return Vector(x=math.cos(dir),y=math.sin(dir))*length

def normalize(vec):
    return vec*(1.0/vec.length())
    
def next_dir(curp,prevp):
    '''
    inputs are 2 dimentional vectors
    to_xy converts (length, dir) to (x,y), or polar to cartisian coordinates
    '''
    away_weight = 1.0
    rand_weight = 0.5
    away_vec = normalize(curp-prevp) *away_weight
    #to_xy converts (length, dir) to
    rand_vec = to_xy(rand_weight,random.random()*2*math.pi)
    result_vec = away_vec + rand_vec
    return result_vec.direction()
    
def next_point(curp,prevp):
    ndir = next_dir(curp,prevp)
    return curp+to_xy(ndir,1)
    
prev_p = Vector(2,-1)
cur_p = Vector(1,1)
for x in range(10):
    new_p = next_point(cur_p,prev_p)
    prev_p = cur_p
    cur_p = new_p
    print(cur_p)