以任意精度浮点计算sympy函数

Question

Given a sympy symbolic function, for example

x=symbols("x")
h=sin(x) 

when one calls

h.subs(x, mpf('1.0000000000000000000000000000000000000000000001')) 

sympy returns a floating point number. The return value is not an mpf.

Is there a convenient way to get sympy to evaluate symbolic standard functions (like exponential and trig functions), using arbitrary precision?

Answer 1

To evaluate an expression, use expr.evalf() , which takes a precision as the first argument (the default is 15). You can substitute expressions using expr.evalf(prec, subs=subs_dict) .

>>> sin(x).evalf(50, subs={x: Float('1.0')})
0.84147098480789650665250232163029899962256306079837