sympy cheat sheet
Transcription
sympy cheat sheet
SymPy Cheatsheet (http://sympy.org) Geometry Basics Sympy help: Declare symbol: Substitution: Numerical evaluation: Expanding: Common denominator: Simplify expression: Constants π: e: ∞: i: pi E oo I help(function) x = Symbol(’x’) expr.subs(old, new) expr.evalf() expr.expand() ratsimp(expr) simplify(expr) Integer(x) Rational(p, q) Float(x) Basic funtions Trigonometric: Cyclometric: Hyperbolic: Area hyperbolic: Exponential: Square root: Logarithm (logb a): Natural logarithm: Gamma (Γ(x)): Absolute value: sin cos tan cot asin acos atan acot sinh cosh tanh coth asinh acosh atanh acoth exp(x) sqrt(x) log(a, b) log(a) gamma(x) abs(x) Calculus lim f (x): x→a limit(f, x, a) lim f (x): limit(f, x, a, dir=’-’) lim f (x): limit(f, x, a, dir=’+’) x→a− x→a+ d f (x): dx ∂ ∂x R f (x, y): f (x) dx : Rb f (x) dx : a Taylor series (at a, deg n) Points: Lines: Circles: Triangles: Area: Intersection: Checking tangency: a = Point(xcoord, ycoord) l = Line(pointA, pointB) c = Circle(center, radius) t = Triangle(a, b, c) object.area intersection(a, b) c.is_tangent(l) diff(f, x) diff(f, x) integrate(f, x) integrate(f, (x, a, b)) f.series(x, a, n) Plot: Zoom: +/−: Rotate X,Y axis: Rotate Z axis: View XY: View XZ: View YZ: View Perspective: Axes Visibility: Axes Colors: Screenshot: Exit plot: Plot(f, [a, b]) R/F or PgUp/PgDn or Numpad +/Arrow Keys or WASD Q and E or Numpad 7 and 9 F1 F2 F3 F4 F5 F6 F8 ESC Discrete math Factorial (n!): Binomial coefficient nk : P Sum ( bn=a expr): Q Product ( bn=a expr): factorial(n) binomial(n, k) summation(expr, (n, a, b)) product(expr, (n, a, b)) Expand (x + y)2 (x − y)(x2 + y): ((x + y)**2 * (x - y) * (x**2 + y)).expand() 1 x sin x − 1 + : x x2 − 1 simplify((1/x) + (x * sin(x) - 1)/(x**2 - 1)) Simplify Matrix definition: Determinant: Inverse: Identity matrix n × n: Zero matrix n × n: Ones matrix n × n: Equations solve(f, x) solve([f, g], [x, y]) dsolve(equation, f(x)) Check if line passing through points (0, 1) and (1, 1) is tangent to circle with center at (5, 5) and radius 3: Circle(Point(5,5), 3).is_tangent( Line(Point(0,1), Point(1,1))) Find roots of x4 − 4x3 + 2x2 − x = 0: solve(x**4 - 4*x**3 + 2*x**2 - x, x) Solve the equations system: x + y = 4, xy = 3: solve([x + y - 4, x*y - 3], [x, y]) Calculate limit of the sequence limit(n**(1/n), n, oo) √ n n: Calculate left-sided limit of the function limit(abs(x)/x, x, 0, dir=’-’) in 0: P 2 Calculate the sum 100 n=0 n : summation(n**2, (n, 0, 100)) m = Matrix([[a, b], [c, d]]) m.det() m.inv() eye(n) zeros(n) ones(n) R Calculate the integral cos3 x dx: integrate(cos(x)**3, x) R∞ Calculate the integral 1 xdx2 : integrate(1/x**2, (x, 1, oo)) Find 10 terms of series expansion of (1/(1 - 2*x)).series(x, 0, 10) LATEX print: Python print: Pretty print: |x| x P 1 Calculate the sum ∞ n=0 n2 : summation(1/n**2, (n, 0, oo)) Linear algebra Printing Equation f (x) = 0: System of equations: Differential equation: Find 100 digits of π e : (pi**E).n(100) Plotting Numbers types Integers (Z): Rationals (Q): Reals (R): Examples print latex() print python() pprint() 00 1 1−2x at 0: Solve the differential equation f (x) + 9f (x) = 1: dsolve(f(x).diff(x, x) + 9*f(x) - 1, f(x))