如何找出Sympy变量是否复杂？ [英] How to find out if the Sympy variable is complex?

问题描述

我正在编写涉及求解此方程的代码

I am writing a code which involves solving this equation

X = solve(Theta_Mod_Eqn*Ramp_Equation/(x+PT) - C, x)

我正在使用sympy库，现在该方程式有7个根，很少有复数，很少是真实的。我无法隔离它们，因为 isinstance（i，complex）始终返回true

I am using sympy library, now the equation has 7 roots few are complex and few are real. I am unable to segregate them because isinstance(i,complex) is always returning true

for i in X:
    if not isinstance(i,complex):
        if (i>-0.01 and i<maxSheaveDisp):
            A = i;

一种情况
i = -0.000581431210287302-0.2540334478167 * I

for one case i = -0.000581431210287302 - 0.2540334478167*I

In:i == complex
Out[39]: False

如何找出变量是否复杂？

How to find out if the variable is complex?

推荐答案

实数是复数集合的子集。因此，每个实数都是一个复数。例如，3是一个复数。

The set of real numbers is a subset of the set of complex numbers. So, every real number is a complex number. For example, 3 is a complex number.

要问的正确问题是如何找出根是否真实。为此，如果我是SymPy符号，则可以使用 i.is_real ：

The correct question to ask is how to find out if a root is real. For that, you can use i.is_real if i is a SymPy symbol:

for i in X:
    if i.is_real:
        if (i>-0.01 and i<maxSheaveDisp):
            A = i

也可以将 im（i）与0 进行比较：如果 im（i）== 0 。这也适用于Python浮动。

One can also compare im(i) to 0: if im(i) == 0. This works for Python floats too.

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