sympa 0.1.0

Symbolic math for pandas

Sympa

Symbolic math for pandas.

Description

Links symbolic expressions created using sympy to columns of data in pandas DataFrames. Any expression created with sympy, which can be “lambdified”, will/should/might work.

Warning

The API design for sympa is subject to change, depending on feedback, if any.

Usage

from pandas import DataFrame
from sympy import symbols
from sympa import domath

df = pd.DataFrame({'x' : [1,2,3,4] * 2, 'y' : [0.1, 0.2] * 4)

# Notice x_-1 and x_-2 are used to reference x @ t=-1, and x @ t=-2.
x, xn1, xn2, y = symbols('x x_-1 x_-2 y')

f = 3.0 * x ** 3 + 2.0 * xn1 ** 2 + xn2 + (y * 2) / 2

df['f'] = domath(df,f)

Docs

For now, there isn’t much documentation. I think it’s pretty straightforward. Check out the /doc folder of the repo on github for more examples.

Requirements

• Sympy >= 0.7.6 but should work with much older versions (untested).

• Pandas >= 0.15 but should work with much older versions (untested).

Python

Works on 2.7, untested on all other versions. It is expected to be ported to 3.4 soon, and likely 2.6 as well.

Install

pip install sympa