88 lines
2.1 KiB
Plaintext
88 lines
2.1 KiB
Plaintext
{
|
|
"cells": [
|
|
{
|
|
"cell_type": "code",
|
|
"execution_count": null,
|
|
"metadata": {},
|
|
"outputs": [],
|
|
"source": [
|
|
"from itertools import chain\n",
|
|
"import numpy as np\n",
|
|
"import math\n",
|
|
"from scipy import sparse\n",
|
|
"from scipy.sparse.linalg import eigsh\n",
|
|
"\n",
|
|
"#sample potential\n",
|
|
"def V_gauss(dr_sqr):\n",
|
|
" return -4*math.exp(-dr_sqr/4)\n",
|
|
"\n",
|
|
"n=3 # no of particles\n",
|
|
"L=14\n",
|
|
"N=6 # no of lattice points\n",
|
|
"mu=1/2 # reduced mass\n",
|
|
"\n",
|
|
"DOF=(n-1)*3 # degrees of freedom after excluding CM\n",
|
|
"\n",
|
|
"s=np.arange(N**DOF) # matrix index\n",
|
|
"\n",
|
|
"# k index for each particle and each dimension\n",
|
|
"k=np.empty((n-1,3),dtype=np.dtype)\n",
|
|
"for dof in range(DOF):\n",
|
|
" k[dof//3,dof%3]=(s%N**(DOF-dof))//N**(DOF-1-dof)-N//2\n",
|
|
"\n",
|
|
"x=k*(L/N) # x coordinate from k index\n",
|
|
"\n",
|
|
"# adding up all non-local interactions\n",
|
|
"V_local=np.zeros(N**DOF)\n",
|
|
"\n",
|
|
"# 2-body interactions\n",
|
|
"V2=np.vectorize(V_gauss)\n",
|
|
"dxs=chain((x[i,:] for i in range(n-1)), (x[i,:]-x[j,:] for (i,j) in np.ndindex((n-1,n-1)) if i<j)) # with last particle + with each other\n",
|
|
"for dx in dxs:\n",
|
|
" dr_sqr=np.sum(dx*dx)\n",
|
|
" V_local+=V2(dr_sqr)"
|
|
]
|
|
},
|
|
{
|
|
"cell_type": "code",
|
|
"execution_count": null,
|
|
"metadata": {},
|
|
"outputs": [],
|
|
"source": [
|
|
"filename = \"temp/V_vals.dat\"\n",
|
|
"\n",
|
|
"with open(filename, 'br') as f:\n",
|
|
" buffer = f.read()\n",
|
|
"\n",
|
|
"V_julia = np.frombuffer(buffer, dtype=np.float32)\n",
|
|
"\n",
|
|
"abs_diff = np.abs(V_local-V_julia)\n",
|
|
"s = np.sum(abs_diff)\n",
|
|
"print(s)"
|
|
]
|
|
}
|
|
],
|
|
"metadata": {
|
|
"kernelspec": {
|
|
"display_name": "base",
|
|
"language": "python",
|
|
"name": "python3"
|
|
},
|
|
"language_info": {
|
|
"codemirror_mode": {
|
|
"name": "ipython",
|
|
"version": 3
|
|
},
|
|
"file_extension": ".py",
|
|
"mimetype": "text/x-python",
|
|
"name": "python",
|
|
"nbconvert_exporter": "python",
|
|
"pygments_lexer": "ipython3",
|
|
"version": "3.9.13"
|
|
},
|
|
"orig_nbformat": 4
|
|
},
|
|
"nbformat": 4,
|
|
"nbformat_minor": 2
|
|
}
|