varius 0.1.10

Perform calculation with various versions of variables

Varius

Perform computations using various versions of variables

Varius is the Latin word for "various."

Install

pip install varius

Usage Examples

import varius
from varius import *

# default variables
cst = vr('cost [usd]', 100)
rev = vr('revenue [usd]', 300)

# expressions: if values are not given the expressions will be symbolic
pft = ex('profit [usd]', rev - cst)
pmg = ex('profit margin', pft.expr/rev)

# show() will display the variables or expressions based on your python env
# if in jupyter notebooks, they will be displayed as beautiful latex equations otherwise as plain texts

with note('default') as d:
    show(cst, rev, pft, pmg)
    pft.grad()
    pmg.grad()
    print(d)

# new case
with note('20% discount', copy='default') as d:
    rev(rev['default'] * 0.8)
    show(cst, rev, pft, pmg)
    pft.grad()
    pmg.grad()
    print(d)


# another case
with note('50% discount', copy='default') as d:
    rev(rev['default'] * 0.5)
    show(cst, rev, pft, pmg)
    pft.grad()
    pmg.grad()
    print(d)

You will get summaries as follows:

Scope version: default
  Variables:
    (cost [usd]) = 100
    (revenue [usd]) = 300
  Expressions:
    (profit [usd]) = 200
    (profit margin) = 2/3
    ∂ [(profit [usd])] / ∂ [(cost [usd])] = -1
    ∂ [(profit [usd])] / ∂ [(revenue [usd])] = 1
    ∂ [(profit margin)] / ∂ [(cost [usd])] = -1/300
    ∂ [(profit margin)] / ∂ [(revenue [usd])] = 1/900

Scope version: 20% discount
  Variables:
    (cost [usd]) = 100
    (revenue [usd]) = 240.0
  Expressions:
    ∂ [(profit [usd])] / ∂ [(cost [usd])] = -1
    ∂ [(profit [usd])] / ∂ [(revenue [usd])] = 1
    ∂ [(profit margin)] / ∂ [(cost [usd])] = -0.00416666666666667
    ∂ [(profit margin)] / ∂ [(revenue [usd])] = 0.00173611111111111
    (profit [usd]) = 140.000000000000
    (profit margin) = 0.583333333333333    

Scope version: 50% discount
  Variables:
    (cost [usd]) = 100
    (revenue [usd]) = 150.0
  Expressions:
    ∂ [(profit [usd])] / ∂ [(cost [usd])] = -1
    ∂ [(profit [usd])] / ∂ [(revenue [usd])] = 1
    ∂ [(profit margin)] / ∂ [(cost [usd])] = -0.00666666666666667
    ∂ [(profit margin)] / ∂ [(revenue [usd])] = 0.00444444444444445
    (profit [usd]) = 50.0000000000000
    (profit margin) = 0.333333333333333