--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NEQGamma.py	Fri Sep 11 21:54:45 2020 +0000
@@ -0,0 +1,210 @@
+#!/usr/bin/env python
+
+# coding: utf-8
+# This script is a modified version of a script written
+# by Steffen Wolf under the GPL v3.0.
+# The original version can be accessed at
+# https://github.com/moldyn/dcTMD/blob/master/NEQGamma.py
+
+import argparse
+import json
+import sys
+
+import numpy as np
+
+import pandas as pd
+
+import scipy
+import scipy.integrate
+from scipy.ndimage.filters import gaussian_filter
+
+
+def get_file_names(list_file):
+    with open(list_file) as f:
+        return [line for line in f.read().split('\n') if line]
+
+
+def NEQGamma(file_names, output, output_frict, vel, T, av, sigma):
+    N = len(file_names)
+    RT = 0.0083144598 * T
+
+    sys.stdout.write("reading data...\n")
+
+    # read in initial data to get length of necessary array
+    test_file = pd.read_csv(file_names[0], delim_whitespace=True,
+                            header=None, skiprows=17, dtype=float)
+    length_data = len(test_file[0].values)
+    full_force_set = np.zeros((N, length_data))
+    x = np.zeros(length_data)
+    t = np.zeros(length_data)
+    t = test_file[0].values
+    x = test_file[0].values * vel
+
+    # read in data
+    for i in range(0, N):
+        current_file_name = file_names[i]
+        sys.stdout.write("reading file {}\n".format(current_file_name))
+        input_file_data = pd.read_csv(current_file_name, delim_whitespace=True,
+                                      header=None, skiprows=17, dtype=float)
+        full_force_set[i, :] = input_file_data[1].values
+
+    # preprocessing
+    # * force average: calculate $\left< f_c (t)\right>_N$.
+    # **Important:** this is an ensemble average over the trajectory ensemble
+    # $N$, not the time average over $t$
+    av_force = np.zeros(length_data)
+    av_forceintegral = np.zeros(length_data)
+    for i in range(length_data):
+        av_force[i] = np.mean(full_force_set[:, i])
+    av_forceintegral[1:] = scipy.integrate.cumtrapz(av_force, x)
+
+    # calculate $\delta f_c(t) = f_c(t) - \left< f_c (t) \right>_N$ for all $t$
+    sys.stdout.write("calculating fluctuations...\n")
+    delta_force_set = np.zeros((N, length_data))
+    for i in range(length_data):
+        delta_force_set[:, i] = full_force_set[:, i] - av_force[i]
+
+    # evaluation
+    # * optimized algorithm for numerical evaluation:
+    #     * integrate: $\int_0^t dt' \delta f_c(t')$ for all $t'$
+    #     * multiply by $\delta f_c(t)$ to yield
+    # $\int_0^t dt'\delta f_c(t) \delta f_c(t')$ for $t$
+    # with all $t' \leq t$ each
+    #     * then calculate the ensemble average
+    # $\left< \int_0^t dt' \delta f_c(t) \delta f_c(t') \right>$
+    int_delta_force_set = np.zeros((N, length_data))
+    for n in range(N):
+        int_delta_force_set[n, 1:] = scipy.integrate.cumtrapz(
+                                        delta_force_set[n, :], t)
+
+    sys.stdout.write("averaging and integrating...\n")
+    intcorr = np.zeros((N, length_data))
+
+    for n in range(N):
+        for i in range(length_data):
+            intcorr[n, i] = delta_force_set[n, i] * int_delta_force_set[n, i]
+            if i % 1000 == 0:
+                sys.stdout.write("Trajectory {:2d} {:3.1f} % done\r".format(
+                    n + 1, (i / length_data) * 100))
+
+    # shape of  $\int_0^t dt' \delta f_c(t) \delta f_c(t')$:
+    sys.stdout.write("final average...\n")
+    av_intcorr = np.zeros(length_data)
+    for i in range(length_data):
+        av_intcorr[i] = np.mean(intcorr[:, i]) / RT
+
+    # autocorrelation function evaluation:
+    #  * calculate $\left< \delta f_c(t) \delta f_c(t') \right>$
+    # for the last $t$
+
+    corr_set = np.zeros((N, length_data))
+    autocorr_set = np.zeros(length_data)
+
+    sys.stdout.write("calculating and processing ACF...\n")
+    for n in range(N):
+        for i in range(length_data):
+            corr_set[n, i] = delta_force_set[
+                n, i] * delta_force_set[n, length_data - 1]
+
+    for i in range(length_data):
+        autocorr_set[i] = np.mean(corr_set[:, i])
+
+    # * Gauss filter:
+    sys.stdout.write("applying Gauss filter...\n")
+    blurr = sigma
+    blurred = np.zeros(length_data)
+    blurred = gaussian_filter(av_intcorr, sigma=blurr)
+
+    # * sliding window average:
+    sys.stdout.write("applying sliding window average...\n")
+    window = av
+    runn_av = np.zeros(length_data)
+    runn_av = np.convolve(av_intcorr, np.ones((window,)) / window, mode='same')
+
+    # * $W_{diss}$ from integration:
+    wdiss = np.zeros(length_data)
+    wdiss[1:] = scipy.integrate.cumtrapz(av_intcorr, x) * vel
+
+    sys.stdout.write("writing output...\n")
+    dist = open(output, "w")
+    frict = open(output_frict, "w")
+
+    dist.write(
+        "#x  force_integral  frict_coeff   wdiss   corrected_force_integral\n")
+    for i in range(length_data):
+        dist.write("{:15.8f} {:20.8f} {:20.8f} {:20.8f} {:20.8f}\n".format(
+            x[i], av_forceintegral[i], av_intcorr[i], wdiss[i],
+            av_forceintegral[i] - wdiss[i]))
+
+    frict.write("""#x   ACF   frict_coeff   """
+                """gauss_filtered_frict_coeff   av_window_frict_coeff\n""")
+    for i in range(length_data):
+        frict.write("{:15.8f} {:20.8f} {:20.8f} {:20.8f} {:20.8f}\n".format(
+                x[i], autocorr_set[i], av_intcorr[i], blurred[i], runn_av[i]))
+
+    dist.close()
+    frict.close()
+
+    sys.stdout.write("Done!\n")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="""dcTMD friciton correction
+        (please cite: Wolf, S., Stock, G. Targeted Molecular Dynamics
+        Calculations of Free Energy Profiles Using a Nonequilibrium
+        Friction Correction. J. Chem. Theory Comput. 2018, 14(12), 6175-6182,
+        DOI: 10.1021/acs.jctc.8b00835). Integrates a constraint force file via
+        trapezoid rule, calculates the NEQ memory friction kernel and friction
+        factors, and performs a friction correction. First column: reaction
+        coordinate in nm calculated via t * vel. Second column: force integral,
+        i.e. the work profile. Third column: friction factors. Fourth column:
+        trapezoid integral (final value) of friction work along reaction
+        coordinate. Fourth column: friction corrected work profile. ATTENTION:
+        Use with python3 or higher!""")
+    parser.add_argument('-i', metavar='<xvg force file>', type=str,
+                        help="""List of xvg constraint force files prefix
+                        as given by Gromacs mdrun -pf option before running
+                        number.""")
+    parser.add_argument('-o', metavar='<combined results>', type=str,
+                        help="""file to write x, dG(x), friction coefficeint by
+                        integration (time resolved), and the friction-corrected
+                        dG(x).""")
+    parser.add_argument('-ofrict', metavar='<combined friction results>',
+                        type=str,
+                        help="""file to write x, ACF, friction coefficeint by
+                        integration (time resolved), gauss filtered friction
+                        coefficient, and slide window averaged friction.""")
+    parser.add_argument('-vel', metavar='<pull velocity>', type=float,
+                        help="""pull velocity in nm/ps for converting simulation
+                        time t into distance x""")
+    parser.add_argument('-T', metavar='<temperature>', type=float,
+                        help='temperature in K')
+    parser.add_argument('-av', metavar='<average window>', type=int,
+                        help="""size of averaging window for displaying
+                        Gamma(x) (recommended: 4 to 20 per 100 data points)""")
+    parser.add_argument('-sigma', metavar='<gauss blurr>', type=int,
+                        help="""sigma value for Gauss filter for displaying
+                        Gamma(x) (recommended: 4 per 100 data points)""")
+    parser.add_argument('-json', metavar='<json>', type=str,
+                        help='JSON file defining cluster membership')
+
+    args = parser.parse_args()
+
+    file_names = get_file_names(args.i)
+    if args.json:
+        with open(args.json) as f:
+            j = json.load(f)
+        file_names_dct = {n: [file_names[int(m)] for m in j[n]] for n in j}
+
+        for cluster in file_names_dct:
+            NEQGamma(file_names_dct[cluster],
+                     'cluster{}_{}'.format(cluster, args.o),
+                     'cluster{}_{}'.format(cluster, args.ofrict),
+                     args.vel, args.T, args.av, args.sigma)
+    else:
+        NEQGamma(file_names, args.o, args.ofrict, args.vel,
+                 args.T, args.av, args.sigma)
+
+
+if __name__ == "__main__":
+    main()