Files
mathgenerator/mathgenerator/funcs/system_of_equations.py
2020-10-20 11:30:55 -04:00

53 lines
2.1 KiB
Python

from .__init__ import *
def systemOfEquationsFunc(range_x=10, range_y=10, coeff_mult_range=10):
# Generate solution point first
x = random.randint(-range_x, range_x)
y = random.randint(-range_y, range_y)
# Start from reduced echelon form (coeffs 1)
c1 = [1, 0, x]
c2 = [0, 1, y]
def randNonZero():
return random.choice(
[i for i in range(-coeff_mult_range, coeff_mult_range) if i != 0])
# Add random (non-zero) multiple of equations (rows) to each other
c1_mult = randNonZero()
c2_mult = randNonZero()
new_c1 = [c1[i] + c1_mult * c2[i] for i in range(len(c1))]
new_c2 = [c2[i] + c2_mult * c1[i] for i in range(len(c2))]
# For extra randomness, now add random (non-zero) multiples of original rows
# to themselves
c1_mult = randNonZero()
c2_mult = randNonZero()
new_c1 = [new_c1[i] + c1_mult * c1[i] for i in range(len(c1))]
new_c2 = [new_c2[i] + c2_mult * c2[i] for i in range(len(c2))]
def coeffToFuncString(coeffs):
# lots of edge cases for perfect formatting!
x_sign = '-' if coeffs[0] < 0 else ''
# No redundant 1s
x_coeff = str(abs(coeffs[0])) if abs(coeffs[0]) != 1 else ''
# If x coeff is 0, dont include x
x_str = f'{x_sign}{x_coeff}x' if coeffs[0] != 0 else ''
# if x isn't included and y is positive, dont include operator
op = ' - ' if coeffs[1] < 0 else (' + ' if x_str != '' else '')
# No redundant 1s
y_coeff = abs(coeffs[1]) if abs(coeffs[1]) != 1 else ''
# Don't include if 0, unless x is also 0 (probably never happens)
y_str = f'{y_coeff}y' if coeffs[1] != 0 else (
'' if x_str != '' else '0')
return f'{x_str}{op}{y_str} = {coeffs[2]}'
problem = f"{coeffToFuncString(new_c1)}, {coeffToFuncString(new_c2)}"
solution = f"x = {x}, y = {y}"
return problem, solution
# Add random (non-zero) multiple of equations to each other
system_of_equations = Generator("Solve a System of Equations in R^2", 23,
"2x + 5y = 13, -3x - 3y = -6", "x = -1, y = 3",
systemOfEquationsFunc)