Choosing a Package¶

This guide helps you decide which QSP packages to depend on for your specific use case.

Start with qsp-stack if…¶

You are new to QSP and want to explore the ecosystem
Your workflow spans multiple packages and you are not ready to specify exact dependencies
You are building a prototype and want full access to all utilities
Dependency footprint is not a concern for your environment

pip install qsp-stack

Use specific packages if…¶

You have a well-defined, narrow use case
You want a minimal dependency footprint in production
You need independent version pinning for specific packages
Your environment has constraints on installed package size

Decision guide¶

"I need quaternion types and math"¶

→ qsp-core

This is the base package. Use it directly if you are:

Building a custom algorithm on top of QSP types
Writing a library that extends the ecosystem
Using quaternion arithmetic without needing transforms or filters

"I need spectral analysis or frequency-domain tools"¶

→ qsp-fft

Use this if you are:

Computing the frequency content of a signal
Working in the frequency domain
Designing frequency-domain filters (paired with qsp-filter)

Note: qsp-fft depends on qsp-core and installs it automatically.

"I need to filter or preprocess a signal"¶

→ qsp-filter

Use this if you are:

Removing noise or artifacts from a signal
Applying bandpass, lowpass, or highpass filtering
Preprocessing sensor data before orientation estimation or modulation

Note: qsp-filter depends on qsp-core.

"I need to work with modulation or communication signals"¶

→ qsp-modulation

Use this if you are:

Generating symbol streams for a communication channel
Implementing or testing a modulation scheme
Working at the physical-layer signal geometry level

Note: qsp-modulation depends on qsp-core. If your workflow also involves filtering conditioned inputs, add qsp-filter.

"I need orientation or attitude estimation"¶

→ qsp-orientation

Use this if you are:

Processing IMU or multi-axis sensor data
Estimating platform attitude or orientation over time
Building a navigation or sensor fusion pipeline

Note: qsp-orientation depends on qsp-core. If your sensors produce noisy data, add qsp-filter for conditioning.

Multi-package workflows¶

Most real-world workflows span more than one package. Common combinations:

Workflow	Packages
Sensor conditioning + orientation	`qsp-filter`, `qsp-orientation`
Spectral analysis + filtering	`qsp-fft`, `qsp-filter`
Communication signal pipeline	`qsp-filter`, `qsp-modulation`
Full signal processing stack	`qsp-stack`
Custom algorithm on QSP types	`qsp-core`

When to stay on qsp-stack¶

If your workflow genuinely spans the full ecosystem and you are not concerned about dependency size, staying on qsp-stack is a valid long-term choice. It provides a single versioned entry point and simplifies upgrades.