[ALPS-users] Question of MC Simulation for XY Model

Hi,

I am just new to ALPS, and I have a question about running MC simulations of XY model:

Following the tutorials, I use python to run the simulations and change the model from “Ising” to “XY”, like:

import pyalps parms = [ { 'LATTICE': "square lattice", 'T': 1, 'J': 1, 'THERMALIZATION': 10000, 'SWEEPS': 400000, 'UPDATE': "cluster", 'MODEL': "XY", 'L': 8 } ] input_file = pyalps.writeInputFiles('data/parmXY', parms) pyalps.runApplication('spinmc', input_file, Tmin=5) result_files = pyalps.getResultFiles(prefix='data/parmXY') data = pyalps.loadMeasurements(result_files)

how can I get some quantities like $$<M_x^2>=<\cos^2\theta>$$, or the nematic $$<N_x>=<\cos 2\theta>$$, where $$\theta$$ is the direction of the spin at each site? Is it possible to get these quantities I want through ALPS?

Really hope someone can give me a hint to do this. Thank you in advance!

Best, Wei