Curve fitting with Python
First we need a NumPy and MatPlotLib modules.
Look at curve fitting explanation from wiki.
Second degree polynomial equation would help us: y=ax^2 + bx + c
This will exactly fit a simple curve to three points.
Using more points we get a nearest possible curve.
# Import modules
from numpy import *
from matplotlib.pyplot import *
# Input data (change it)
# X and Y points must have same length
x = [1, 2, 4, 6]
y = [10, 3, 7, -6]
# (a, b, c) coefficients computation
coefficients = polyfit(x, y, 2)
# With coefficients we make a polynomial object
poly = poly1d(coefficients)
# Create point series
xs = arange(min(x)-1, max(x)+1, 0.05)
# Calculate resultant series
ys = poly(xs)
# Finally draw everything
plot(xs, ys)
plot(x, y, 'o')
# X and Y axis label
ylabel('y')
xlabel('x')
# And show
show()
Using 3 points:
x = [1, 2, 4]
y = [10, 3, 7]
Using 4 points:
x = [1, 2, 4, 6]
y = [10, 3, 7, -6]
