A calculator designed for propagation of uncertainties.
Use online: https://wucha.herokuapp.com
In the IB physics syllabus, sub-topic 1.2 treats uncertainties and errors. Specifically, the following formulae are given:
- If:
y = a ± b
, then:Δy = Δa + Δb
- If:
y = ab / c
, then:Δy / y = Δa / a + Δb / b + Δc / c
- If:
y = a^n
, then:Δy / y = |n Δa / a|
A bit puzzled by how these formulae are derived, I did some investigations to find out that the IB uses an approximation of the variance formula which assumes independent variables:
Δf(x, y, z, ...) = ∑ |∂f / ∂i| Δi, i = x, y, z, ...
Using sympy, I built a calculator that propagates the uncertainty using the above formula. This calculator might come in handy for analysis in lab reports when you have complex equations.
- backend: Python
Flask
- frontend: Javascript
React
- hosting:
Heroku
(with python and node.js buildpacks)