Frequency coalescence

Simulates the coalescence of peaks in an ensemble of variable-frequency oscillators, often encountered with exchanging protons in NMR experiments (also an exercise in using JavaScript generators for signal generation/processing). The ¹H signal emitted by the above system depends on which one of X or Y the H is bonded to. With slow exchange (f_exchange ≪ | f_X-H – f_Y-H |), two distinct peaks result:

Fast exchange (f_exchange ≫ | f_X-H – f_Y-H |) gives a single peak at the average of f_X-H and f_Y-H:

Modifying the simulation

npm install
npm run dev # or npm run build

Then go to http://localhost:8000.

TODO

• Display the (phase-adjusted) real part of the FFT instead of its magnitude.
• Package fft-asm.js as npm package, then pull it in as a proper dependency.

Credits

• g200kg/Fft-asm.js for FFT calculation