--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sucos_cluster.py	Wed Oct 02 12:57:54 2019 -0400
@@ -0,0 +1,134 @@
+#!/usr/bin/env python
+"""
+Cluster a set of molecules based on their 3D overlays as determined by the SuCOS score.
+
+This will generate a set of SD files, one for each cluster of molecules (presumably corresponding to a
+binding pocket in the protein target).
+
+
+SuCOS is the work of Susan Leung.
+GitHub: https://github.com/susanhleung/SuCOS
+Publication: https://doi.org/10.26434/chemrxiv.8100203.v1
+"""
+
+import sucos, utils
+import argparse, gzip
+from rdkit import Chem
+import numpy as np
+import pandas as pd
+from scipy.cluster.hierarchy import linkage, fcluster
+
+### start main execution #########################################
+
+
+def calc_distance_matrix(mols):
+    """
+    Calculate a full distance matrix for the given molecules. Identical molecules get a score of 0.0 with the maximum
+    distance possible being 1.0.
+    :param mols: A list of molecules. It must be possible to iterate through this list multiple times
+    :return: A NxN 2D array of distance scores, with N being the number of molecules in the input
+    """
+
+    # TODO - do we need to calculate both sides of the matrix? Tanimoto is supposed to be a symmetric distance measure,
+    #  but the matrix that is generated does not seem to be symmetric.
+
+    mol_fm_tuples = []
+    for mol in mols:
+        features = sucos.getRawFeatures(mol)
+        mol_fm_tuples.append((mol, features))
+
+    matrix = []
+    for tuple1 in mol_fm_tuples:
+        tmp = []
+        for tuple2 in mol_fm_tuples:
+            if tuple1[0] == tuple2[0]:
+                tmp.append(0.0)
+            else:
+                #utils.log("Calculating SuCOS between", mol1, mol2)
+                sucos_score, fm_score, tani_score = sucos.get_SucosScore(tuple1[0], tuple2[0],
+                    tani=True, ref_features=tuple1[1], query_features=tuple2[1])
+                tmp.append(1.0 - sucos_score)
+        matrix.append(tmp)
+
+
+    return matrix
+
+
+def cluster(matrix, threshold=0.8):
+    """
+    Cluster the supplied distance matrix returning an array of clusters.
+    :param matrix: the distance matrix, as calculated with the calc_distance_matrix function.
+    :param threshold: The clustering cuttoff. The default of 0.8 is a reasonable value to use.
+    :return: An array of clusters, each cluster being an array of the indices from the matrix.
+    """
+
+    indexes = [x for x in range(0, len(matrix))]
+    cols = [x for x in range(0, len(matrix[0]))]
+    #utils.log("indexes", indexes)
+    #utils.log("cols", cols)
+    df = pd.DataFrame(matrix, columns=cols, index=indexes)
+    utils.log("DataFrame:", df.shape)
+    #utils.log(df)
+    indices = np.triu_indices(df.shape[0], k=1)
+    #utils.log("Indices:", indices)
+    t = np.array(df)[indices]
+    Z = linkage(t, 'average')
+    lig_clusters = []
+    cluster_arr = fcluster(Z, t=threshold, criterion='distance')
+    for i in range(np.amax(cluster_arr)):
+        clus = df.columns[np.argwhere(cluster_arr==i+1)]
+        lig_clusters.append([x[0] for x in clus.tolist()])
+
+    utils.log("Clusters", lig_clusters)
+    return lig_clusters
+
+def write_clusters_to_sdfs(mols, clusters, basename, gzip=False):
+    """
+    Write the molecules to SDF files, 1 file for each cluster.
+    :param mols The molecules to write:
+    :param clusters The clusters, as returned by the cluster function:
+    :param basename The basename for the file name. e.g. if basename is 'output' then files like
+    output1.sdf, output2.sdf will be written:
+    :param gzip Whether to gzip the output
+    :return:
+    """
+
+    i = 0
+    for cluster in clusters:
+        i += 1
+        filename = basename + str(i) + ".sdf"
+        if gzip:
+            filename += ".gz"
+        utils.log("Writing ", len(cluster), "molecules in cluster", i, "to file", filename)
+        output_file = utils.open_file_for_writing(filename)
+        writer = Chem.SDWriter(output_file)
+        for index in cluster:
+            mol = mols[index]
+            writer.write(mol)
+        writer.flush()
+        writer.close()
+        output_file.close()
+
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Clustering with SuCOS and RDKit')
+    parser.add_argument('-i', '--input', help='Input file in SDF format. Can be gzipped (*.gz).')
+    parser.add_argument('-o', '--output', default="cluster", help="Base name for output files in SDF format. " +
+                                               "e.g. if value is 'output' then files like output1.sdf, output2.sdf will be created")
+    parser.add_argument('--gzip', action='store_true', help='Gzip the outputs generating files like output1.sdf.gz, output2.sdf.gz')
+    parser.add_argument('-t', '--threshold', type=float, default=0.8, help='Clustering threshold')
+
+    args = parser.parse_args()
+    utils.log("SuCOS Cluster Args: ", args)
+
+    input_file = utils.open_file_for_reading(args.input)
+    suppl = Chem.ForwardSDMolSupplier(input_file)
+    mols = list(suppl)
+    matrix = calc_distance_matrix(mols)
+    clusters = cluster(matrix, threshold=args.threshold)
+    write_clusters_to_sdfs(mols, clusters, args.output, gzip=args.gzip)
+
+
+if __name__ == "__main__":
+    main()
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