bestFit

About

bestFit is a synchronous python module that uses matplotlib and numpy to plot the best fit line of a given set of coordinates.

Github page: https://github.com/SebassNoob/bestFit

Dependencies:

matplotlib
numpy

To import: use import bestFit.main as bf

  • take note of the capitalisation.

Quickstart

This is how to plot a basic graph based on a list of coordinates.

  1. Create a file named index.py in root

  2. To import the module, use import bestFit.main as bf (or any similar shorthand)

  3. Define a list of coordinates, for example: my_coords = [(0,0),(1,3),(2,3),(4,7),(8,0),(-1,0.33)]

  4. Plot the graph like this:

import bestFit.main as bf

my_coords = [(0,0),(1,3),(2,3),(4,7),( 8,0),(-1,0.33)]

      def check_for_anomaly(x,y):
      #checks for anomalies in points, eg: if the x coordinate of a given point is >1000, return True else return False (or None)
      if x>1000:
              return True
      return None
# creates a linear line from the given coordinates, with a green line and green points.
line = bf.create_line_from_raw(line_name="mygraph",linestyle="g-",pointstyle="go"coords = my_coords, n_power =1 , anomaly_check = check_for_anomaly)
line.plot()
show_graph()

  1. Then, run in console: python3 index.py

  2. A line with name mygraph a green solid plotted line, and points on that line displayed as green circles, should be shown.

Classes

class Coordinate(x: str or float, y: str or float, anomaly: bool = False)

The basic coordinate: contains a x and y variable, as well as if the coordinate is an anomaly.

Anomaly values are ignored when plotting a best fit line.

Attributes:

x (float)

A x coordinate.

y (float)

A y coordinate.

anomaly (bool, optional)

Defaults to False. If True, point is considered an anomaly and will not be taken into consideration when plotting.

Methods:

__str__

returns (x,y)

__repr__

returns repr(self.__dir__())

class Line(list_of_coords: list, n_power: int)

A Line object. list_of_coords is a list containing Coordinate objects.

n_power refers to the polynomial power when finding the best fit line. For example, when n_power = 1, Line is linear in the form y = mx + c, but when n_power = 2, Line is a curve in the form y=ax^2 + bx + c.

Attributes:

name (str, optional)

The name of the line used and displayed in the legend. This defaults to a string of numpy.ndarray with the coefficients of the line.

linestyle (str) and pointstyle (str)

The style of the best fit line and the points plotted. Defaults to “-” and “o” respectively. Available types:

types of styles accepted types of colors accepted

Adapted from https://matplotlib.org/2.1.2/api/_as_gen/matplotlib.pyplot.plot.html

eg:

"b-" => a blue solid line
"w-." => a white dash-dot line
"ro" => red circle markers
"kx" => black x markers

x_points (list)

A list of x points provided

y_points (list)

A list of y points provided

invalid_x_points (list)

A list of x points that are considered “anomalies”. See Coordinate class.

invalid_y_points (list)

A list of y points that are considered “anomalies”. See Coordinate class.

polynomial_coefficients (list)

The coefficients to the solved line equation. eg. [1.0,2.0,3.0] is x^2 + 2x + 3

solved_y (list)

Defaults to y_points. If smoothen_line is called (See smoothe_line class function), this will contain more values for y solved with polynomial_coefficients.

solved_x (list)

Defaults to x_points. If smoothen_line is called (See smoothen_line class function), this will contain more values for x solved with polynomial_coefficients.

self.smoothness (int)

The “smoothness” of the graph. A greater value means more smooth. Defaults to None

n (int)

The power of n used for calculation.

Methods:

__str__

returns a list of tuples in the form (x,y) eg. [(0,0),(1,2),(2,4)]

__repr__

returns repr(self.__dir__())

calculate()

Based on given valid points, this will find the coefficients of the polynomial of the best fit line, then calculate solved_x and solved_y, then sort.

returns None

smoothen_line(accuracy: int= None)

Smooths a line. Useful when n_power > 1

returns (self.solved_x, self.solved_y)

plot()

Plots the line, but does not show it.

returns None

add_point(coord: Coordinate)

Adds a point to the Line object. Parameter passed must be a Coordinate object. eg. line.add_point(Coordinate(1,2))

returns (x,y) where x and y are the x and y values of the Coordinate object.

remove_point(coord: Coordinate)

Removes a point from the Line object. Parameter passed must be a Coordinate object. eg. line.remove_point(Coordinate(6,9))

returns (x,y) where x and y are the x and y values of the Coordinate object.

Functions

Note: args marked after * are keyword-specified. Google “python **kwargs” for more info.

eg: .. code-block:: python

import bestFit.main as bf

#where some_method is defined as follows: #some_method(arg1,*,arg2)

bf.some_method(2,arg2=”hello world”)

create_line_from_file(*,line_name:str =None,linestyle = None,pointstyle=None, path: str, n_power: int=1, anomaly_check=None)

Creates a line from a .txt (only) file. An example of a txt file:

1,2
3,4
5,6
-1.2,4
0,0

line_name (str, optional): the name of the line to be shown on the legend. Defaults to the coefficients of the polynomial of the line.

linestyle (str): The style of the line. See the Line.linestyle attribute for list of accepted styles.

pointstyle (str): The style of the points. See the Line.pointstyle attribute for list of accepted styles.

path (str): the path to your file

n_power (int, optional): the n_power of your line (See Line object)

anomaly_check (function, optional): a function of parameters (x,y). Checks if a point specified is invalid and returns True if so.

eg.

def check(x,y):
  if y>0:
    return True
  return False

Returns a Line() object.

create_line_from_raw(*,line_name:str =None,linestyle = None, pointstyle = None,coords:list, n_power: int=1, anomaly_check=None)

Creates a line from a list of tuples containing x,y points.

coords (list): list of coords

eg. hi = [(0,0),(1,1),(2,3)]

line_name (str, optional): the name of the line to be shown on the legend. Defaults to the coefficients of the polynomial of the line.

linestyle (str): The style of the line. See the Line.linestyle attribute for list of accepted styles.

pointstyle (str): The style of the points. See the Line.pointstyle attribute for list of accepted styles.

n_power (int, optional): the n_power of your line (See Line object)

anomaly_check (function, optional): a function of parameters (x,y). Checks if a point specified is invalid and returns True if so.

eg.

def check(x,y):
  if y>0:
    return True
  return False

Returns a Line() object.

show_graph(block=None)

The MOST IMPORTANT METHOD. Shows the entire graph based on the Line() classes initialised.

block (bool, optional): Blocks the code flow to show the graph. Defaults to True.

close_graph()

Closes the current graph displayed.

save_fig(path, format)

Saves the graph to a specified filename.

path (str): Path of the file one wants to save to.

format (str, optional): Format of the file saved. Defaults to “png”

The end:)