skills/sympy/references/core_capabilities.md
Symbolic computation basics, calculus, equation solving, matrices and linear algebra, physics and mechanics, advanced mathematics, and code generation and output. Per-topic detail is in the other reference files in this directory.
Creating symbols and expressions:
from sympy import symbols, Symbol
x, y, z = symbols('x y z')
expr = x**2 + 2*x + 1
# With assumptions
x = symbols('x', real=True, positive=True)
n = symbols('n', integer=True)
Simplification and manipulation:
from sympy import simplify, expand, factor, cancel
simplify(sin(x)**2 + cos(x)**2) # Returns 1
expand((x + 1)**3) # x**3 + 3*x**2 + 3*x + 1
factor(x**2 - 1) # (x - 1)*(x + 1)
For detailed basics: See references/core-capabilities.md
Derivatives:
from sympy import diff
diff(x**2, x) # 2*x
diff(x**4, x, 3) # 24*x (third derivative)
diff(x**2*y**3, x, y) # 6*x*y**2 (partial derivatives)
Integrals:
from sympy import integrate, oo
integrate(x**2, x) # x**3/3 (indefinite)
integrate(x**2, (x, 0, 1)) # 1/3 (definite)
integrate(exp(-x), (x, 0, oo)) # 1 (improper)
Limits and Series:
from sympy import limit, series
limit(sin(x)/x, x, 0) # 1
series(exp(x), x, 0, 6) # 1 + x + x**2/2 + x**3/6 + x**4/24 + x**5/120 + O(x**6)
For detailed calculus operations: See references/core-capabilities.md
Algebraic equations:
from sympy import solveset, solve, Eq
solveset(x**2 - 4, x) # {-2, 2}
solve(Eq(x**2, 4), x) # [-2, 2]
Systems of equations:
from sympy import linsolve, nonlinsolve
linsolve([x + y - 2, x - y], x, y) # {(1, 1)} (linear)
nonlinsolve([x**2 + y - 2, x + y**2 - 3], x, y) # (nonlinear)
Differential equations:
from sympy import Function, dsolve, Derivative
f = symbols('f', cls=Function)
dsolve(Derivative(f(x), x) - f(x), f(x)) # Eq(f(x), C1*exp(x))
For detailed solving methods: See references/core-capabilities.md
Matrix creation and operations:
from sympy import Matrix, eye, zeros
M = Matrix([[1, 2], [3, 4]])
M_inv = M**-1 # Inverse
M.det() # Determinant
M.T # Transpose
Eigenvalues and eigenvectors:
eigenvals = M.eigenvals() # {eigenvalue: multiplicity}
eigenvects = M.eigenvects() # [(eigenval, mult, [eigenvectors])]
P, D = M.diagonalize() # M = P*D*P^-1
Solving linear systems:
A = Matrix([[1, 2], [3, 4]])
b = Matrix([5, 6])
x = A.solve(b) # Solve Ax = b
For comprehensive linear algebra: See references/matrices-linear-algebra.md
Classical mechanics:
from sympy.physics.mechanics import dynamicsymbols, LagrangesMethod
from sympy import symbols
# Define system
q = dynamicsymbols('q')
m, g, l = symbols('m g l')
# Lagrangian (T - V)
L = m*(l*q.diff())**2/2 - m*g*l*(1 - cos(q))
# Apply Lagrange's method
LM = LagrangesMethod(L, [q])
Vector analysis:
from sympy.physics.vector import ReferenceFrame, dot, cross
N = ReferenceFrame('N')
v1 = 3*N.x + 4*N.y
v2 = 1*N.x + 2*N.z
dot(v1, v2) # Dot product
cross(v1, v2) # Cross product
Quantum mechanics:
from sympy.physics.quantum import Ket, Bra, Operator, Commutator
A, B = Operator('A'), Operator('B')
psi = Ket('psi')
comm = Commutator(A, B).doit()
For detailed physics capabilities: See references/physics-mechanics.md
The skill includes comprehensive support for:
For detailed advanced topics: See references/advanced-topics.md
Convert to executable functions:
from sympy import lambdify
import numpy as np
expr = x**2 + 2*x + 1
f = lambdify(x, expr, 'numpy') # Create NumPy function
x_vals = np.linspace(0, 10, 100)
y_vals = f(x_vals) # Fast numerical evaluation
Generate C/Fortran code:
from sympy.utilities.codegen import codegen
[(c_name, c_code), (h_name, h_header)] = codegen(
('my_func', expr), 'C'
)
LaTeX output:
from sympy import latex
latex_str = latex(expr) # Convert to LaTeX for documents
For comprehensive code generation: See references/code-generation-printing.md