Help with Sympy Sets

[Flexico Crux]

I'm looking for a way to solve an equation within an interval and return a list of the values. Solve doesn't guarantee to catch every solution, but Solveset seems to get me partway there:
>>> solveset(sin(x) - sqrt(2)/2, x)
⎧        3⋅π        ⎫   ⎧        π        ⎫
⎨2⋅n⋅π + ─── | n ∊ ℤ⎬ ∪ ⎨2⋅n⋅π + ─ | n ∊ ℤ⎬
⎩         4         ⎭   ⎩        4        ⎭
(that may not look right in a non-monospace font)
That's great and all, but how do I turn that into a list of values, say, between -2*pi and pi?

[Aaron Meurer]

You can iterate through the solution sets, using a for loop or iter(solution). If you want to limit it to -2*pi to pi first intersect with Interval(-2*pi, pi). 

In [7]: solveset(sin(x) - sqrt(2)/2, x).intersect(Interval(-2*pi, pi))

Out[7]:

⎧-7⋅π   -5⋅π   π  3⋅π⎫

⎨─────, ─────, ─, ───⎬

⎩  4      4    4   4 ⎭

That gives you a FiniteSet, which you can convert to a list with list().

Aaron Meurer

[Shekhar Prasad Rajak]

Hello,

You can use its 3rd parameter domain=Interval(start, end) : 

```

In [4]:  solveset(sin(x) - sqrt(2)/2, x, Interval(-2*pi, 2*pi))
Out[4]:

⎧-7⋅π   -5⋅π   π  3⋅π⎫
⎨─────, ─────, ─, ───⎬
⎩  4      4    4   4 ⎭

```

--

Shekhar

[Flexico Crux]

Those don't work for me! I'm using Sympy 1.0 with Python 2.7.12.

[code]

>>> solveset(sin(x)-sqrt(2)/2, x, Interval(-2*pi, 2*pi))

⎧        3⋅π        ⎫   ⎧        π        ⎫

⎨2⋅n⋅π + ─── | n ∊ ℤ⎬ ∪ ⎨2⋅n⋅π + ─ | n ∊ ℤ⎬

⎩         4         ⎭   ⎩        4        ⎭

>>> solveset(sin(x)-sqrt(2)/2, x).intersect(Interval(-2*pi, 2*pi))

⎛              ⎧        3⋅π        ⎫⎞   ⎛              ⎧        π   

⎜[-2⋅π, 2⋅π] ∩ ⎨2⋅n⋅π + ─── | n ∊ ℤ⎬⎟ ∪ ⎜[-2⋅π, 2⋅π] ∩ ⎨2⋅n⋅π + ─ | 

⎝              ⎩         4         ⎭⎠   ⎝              ⎩        4   

     ⎫⎞

n ∊ ℤ⎬⎟

     ⎭⎠

[/code]

[Shekhar Prasad Rajak]

You can install latest repo version from this link: https://github.com/sympy/sympy/archive/master.zip

--

Shekhar 

[Flexico Crux]

Ah, that did the trick! Thank you.