diff --git a/linguistic.py b/linguistic.py
new file mode 100644
index 0000000..565ca1b
--- /dev/null
+++ b/linguistic.py
@@ -0,0 +1,255 @@
+from math import sqrt
+import numpy as np
+from utils.hsk import *
+from utils.clausal import *
+from utils.coll import *
+from utils.bidep import *
+from utils.const import *
+
+
+def get_lexical_indices(text_wordlist, text_level_dict):
+    lexical_indices = {}
+    sophistication2 = (text_level_dict[5] + text_level_dict[6] + text_level_dict[7]) / sqrt(len(text_wordlist))
+    lexical_indices['LEXICAL_RTTR'] = len(set(text_wordlist)) / sqrt(len(text_wordlist))
+    lexical_indices['LEXICAL_SOP2'] = sophistication2
+    return lexical_indices
+
+
+def get_clausal_indices(sent_length_list, clause_length_list, T_unit_length_list, max_depth_list):
+    clausal_indices = {}
+    # length based
+    clausal_indices['MLS'] = np.mean(sent_length_list)
+    clausal_indices['MLC'] = np.mean(clause_length_list)
+    clausal_indices['MLTU'] = np.mean(T_unit_length_list)
+    # unit based
+    clausal_indices['NCPS'] = len(clause_length_list) / len(sent_length_list)
+    clausal_indices['NTPS'] = len(T_unit_length_list) / len(sent_length_list)
+    # tree based
+    clausal_indices['MEAN_TREE_DEPTH'] = np.mean(max_depth_list)
+    clausal_indices['MAX_TREE_DEPTH'] = max(max_depth_list)
+    return clausal_indices
+
+
+def get_coll_indices(collocation_list):
+    coll_indices = {}
+    coll_num = len(collocation_list)
+    sqrt_coll_num = sqrt(coll_num)
+
+    # coll_RTTR
+    set_colls = set(collocation_list)
+    coll_indices['COLL_RTTR'] = len(set_colls) / sqrt_coll_num
+
+    # unique_RTTR
+    unique_colls = [coll for coll in collocation_list if isUniqueColl(coll)]
+    set_unique_colls = set(unique_colls)
+    coll_indices['UNIQUE_RTTR'] = len(set_unique_colls) / (sqrt(len(unique_colls)) + 1)
+
+    # general_RTTR
+    general_colls = [coll for coll in collocation_list if coll not in set_unique_colls]
+    set_general_colls = set(general_colls)
+    general_coll_diversity = len(set_general_colls) / sqrt(len(general_colls))
+    coll_indices['GENERAL_RTTR'] = general_coll_diversity
+
+    # unique_RATIO
+    # coll_indices['UNIQUE_RATIO2'] = len(unique_colls) / coll_num
+    coll_indices['UNIQUE_RATIO2'] = len(unique_colls) / sqrt_coll_num
+
+    # lowfreq_RATIO
+    lowfreq_collls = [coll for coll in collocation_list if isLowFreqColl(coll)]
+    # coll_indices['LOWFREQ_RATIO1'] = len(lowfreq_collls) / coll_num
+    coll_indices['LOWFREQ_RATIO2'] = len(lowfreq_collls) / sqrt_coll_num
+
+    # coll indices based on different types
+    coll_types = ['VO', 'SP', 'AN', 'AP', 'CN*', 'PP*', 'PV*', 'PC*']
+    coll_type_dict = {k: [] for k in coll_types}
+
+    for coll in collocation_list:
+        typ = coll_dict[coll.split('\t')[-1]]
+        coll_type_dict[typ].append(coll)
+
+    for ct, v in coll_type_dict.items():
+        coll_indices[ct + '_RATIO'] = len(v) / len(collocation_list)
+        coll_indices[ct + '_RTTR'] = 0
+        if v:
+            coll_indices[ct + '_RTTR'] = len(set(v)) / sqrt(len(v))
+
+    return coll_indices
+
+
+def get_ngram_indices(text_bigrams, text_trigrams):
+    '''
+    param: 
+     - text_bigrams: <type> list
+     - text_trigrams: <type> dict
+    return :
+     - ngram_indices: <type> dict
+       * bi_rttr, bi_sop2
+       * tri_rttr, tri_sop2
+       * each type of dep: rttr, ratio
+    '''
+    ngram_indices = {}
+    trigram_list = []
+    for trigrams in text_trigrams.values():
+        trigram_list.extend(trigrams)
+
+    # diversity
+    ngram_indices['BIGRAM_RTTR'] = len(set(text_bigrams)) / sqrt(len(text_bigrams))
+    ngram_indices['DEP_RTTR'] = len(set(trigram_list)) / sqrt(len(trigram_list))
+
+    # sophistication
+    sophis_bi = [b for b in text_bigrams if is_sophis_bigram(b)]
+    sophis_tri = [t for t in trigram_list if is_sophis_trigram(t)]
+    # bi_sop1 = len(sophis_bi) / len(text_bigrams)
+    ngram_indices['BIGRAM_SOP2'] = len(sophis_bi) / sqrt(len(text_bigrams))
+    # tri_sop1 = len(sophis_tri) / len(trigram_list)
+    ngram_indices['DEP_SOP2'] = len(sophis_tri) / sqrt(len(trigram_list))
+
+    # rttr and ratio for each dep label
+    deplabels = ["HED", "COO", "SBV", "ADV", "ATT", "VOB", "FOB", "POB", "IOB", "DBL", "RAD", "CMP", "LAD"]
+    for label in deplabels:
+        ngram_indices[label + '_RTTR'] = 0
+        ngram_indices[label + '_RATIO'] = 0
+        if label in text_trigrams:
+            trigrams = text_trigrams[label]
+            ngram_indices[label + '_RTTR'] = len(set(trigrams)) / sqrt(len(trigrams))
+            ngram_indices[label + '_RATIO'] = len(trigrams) / len(trigram_list)
+
+    return ngram_indices
+
+
+def get_dep_distance(depdist):
+    dist_indices = {}
+    sum_dist, num_dist = 0, 0
+
+    deplabels = ["COO", "SBV", "ADV", "ATT", "VOB", "FOB", "POB", "IOB", "DBL", "RAD", "CMP", "LAD"]
+    for label in deplabels:
+        dist_indices[label + '_DIST'] = 0
+        if label in depdist:
+            distances = depdist[label]
+            dist_indices[label + '_DIST'] = np.mean(distances)
+            sum_dist += sum(distances)
+            num_dist += len(distances)
+
+    dist_indices['MEAN_DIST'] = sum_dist / num_dist
+
+    return dist_indices
+
+
+def get_construction_indices(constructions, text_length, const_num):
+    '''
+    ratio and density indices from level 1 to 5
+    '''
+    const_indices = {'CONST_DENSITY': const_num / text_length}
+
+    for i in range(1, 6):
+        level_const = constructions[i]
+        const_indices['CONST' + str(i) + '_RATIO'] = len(level_const) / const_num
+        const_indices['CONST' + str(i) + '_DENSITY'] = len(level_const) / text_length
+
+    # combine level 1&2 to low, level 4&5 to high, level 3 by default the mid
+    const_indices['CONST_LOW_RATIO'] = const_indices['CONST1_RATIO'] + const_indices['CONST2_RATIO']
+    const_indices['CONST_HIGH_RATIO'] = const_indices['CONST4_RATIO'] + const_indices['CONST5_RATIO']
+    const_indices['CONST_LOW_DENSITY'] = const_indices['CONST1_DENSITY'] + const_indices['CONST2_DENSITY']
+    const_indices['CONST_HIGH_DENSITY'] = const_indices['CONST4_DENSITY'] + const_indices['CONST5_DENSITY']
+
+    return const_indices
+
+
+def getLinguisticIndices(text_dict):
+    ''' lexical
+        clausal
+        collocation based
+        bigram and dependency based
+        construction based
+    '''
+
+    indices = {}
+
+    # for lexical
+    text_wordlist, text_level_dict = [], {k: 0 for k in range(1, 8)}
+
+    # for clausal: length based
+    sent_length_list, clause_length_list, T_unit_length_list = [], [], []
+
+    # for clausal: tree based
+    max_depth_list = []
+
+    # for collocation
+    collocation_list = []
+
+    # for bigram and dependency triples
+    text_bigrams, text_trigrams, text_depdists = [], {}, {}
+
+    # text constructions
+    text_constructions = {i: [] for i in range(1, 6)}
+
+    # get linguistic features for one text
+    for sent_id, info in text_dict.items():
+
+        sent, wordlist, wplist = info['sent'], info['wordlist'], info['wplist']
+        worddict = info['worddict']
+
+        # lexical features
+        level_dict = level_analyze(sent, wordlist, wplist)
+        wordlist = [w for w in wordlist if isWordChinese(w)]  # 去除标点数字英文等
+        text_wordlist.extend(wordlist)
+        for level, wl in level_dict.items():
+            text_level_dict[level] += wl
+
+        # clausal units
+        if not re.search('[，。？！；……]', sent):
+            continue
+        sent_length, clause_lengths, T_unit_lengths = clausal_index(sent, worddict)
+        sent_length_list.append(sent_length)
+        clause_length_list.extend(clause_lengths)
+        T_unit_length_list.extend(T_unit_lengths)
+        max_depth = getTreePath(worddict)
+        max_depth_list.append(max_depth)
+
+        # collocations
+        collocations = getColl(worddict)
+        collocation_list.extend(collocations)
+
+        # bigrams and dependency trigrams
+        bigrams = get_bigrams(wplist)
+        text_bigrams.extend(bigrams)
+        text_trigrams, text_depdists = get_dep_trigrams(worddict, text_trigrams, text_depdists)
+
+        # constructions
+        text_constructions = getLevelConstruction(worddict, sent, text_constructions)
+
+        ############### linguistic feature extraction done ###############
+
+    # update length indices
+    text_length = sum(sent_length_list)
+    indices['CHAR_NUM'] = text_length
+    indices['WORD_NUM'] = len(text_wordlist)
+
+    # update lexical indices
+    if len(text_wordlist):
+        lexical_indices = get_lexical_indices(text_wordlist, text_level_dict)
+        indices.update(lexical_indices)
+
+    # udpate clausal indices
+    if sent_length_list:
+        clausal_indices = get_clausal_indices(sent_length_list, clause_length_list, T_unit_length_list, max_depth_list)
+        indices.update(clausal_indices)
+
+    # update collocation based indices
+    if collocation_list:
+        coll_indices = get_coll_indices(collocation_list)
+        indices.update(coll_indices)
+
+    # update bigram and dependency based indices
+    if text_bigrams:
+        ngram_indices = get_ngram_indices(text_bigrams, text_trigrams)
+        dist_indices = get_dep_distance(text_depdists)
+        indices.update(ngram_indices)
+        indices.update(dist_indices)
+
+    const_num = sum([len(v) for v in text_constructions.values()])
+    if const_num:
+        const_indices = get_construction_indices(text_constructions, text_length, const_num)
+        indices.update(const_indices)
+
+    return indices