Merge pull request #6442 from jwj61/regularfamilys

Seems like there was enough time for comments.  Of course, it can always be improved.

Author: jwj61

lmfdb/galois_groups/templates/gg-show-group.html

@@ -118,7 +118,6 @@ <h2>{{KNOWL('group.complex_character_table', 'Character table')}}</h2>
 
   <p>{{place_code('char_table')}}</p>
 
-
 {% if info.int_reps %}
 <h2>{{ KNOWL('gg.int_modules', title='Indecomposable integral representations') }}</h2>
 <table>
@@ -165,4 +164,20 @@ <h2>{{ KNOWL('gg.int_modules', title='Indecomposable integral representations')
   {% endif %}
 {% endif %}
 
+<h2>{{ KNOWL('gg.regular_extension', title='Regular extensions') }}</h2>
+      {% if not info.wgg.regulars %}
+        <p>Data not computed</p>
+      {% else %}
+      <p>
+        <table>
+        {% for model in info.wgg.regulars %}
+          <tr><td style="vertical-align: top">$f_{ {{ loop.index }} } =$</td>
+              <td> {{ model[0]|safe }}</td></tr>
+          <tr><td></td><td> {{ model[1]|safe }}</td></tr>
+        {% endfor %}
+        </table>
+      </p>
+      {% endif %}
+
+
 {% endblock %}

lmfdb/galois_groups/transitive_group.py

@@ -8,7 +8,7 @@
 import yaml
 from flask import render_template
 
-from lmfdb.utils import list_to_latex_matrix, integer_divisors, sparse_cyclotomic_to_mathml
+from lmfdb.utils import list_to_latex_matrix, integer_divisors, sparse_cyclotomic_to_mathml, raw_typeset, display_knowl
 from lmfdb.groups.abstract.main import abstract_group_namecache, abstract_group_display_knowl
 from lmfdb.groups.abstract.web_groups import WebAbstractGroup
 
@@ -74,6 +74,16 @@ def cyclestrings(perm):
 def compress_cycle_type(ct):
     bits = [(str(z), f'^{{{c}}}' if c > 1 else '' ) for z, c in sorted(Counter(ct).items(),reverse=True)]
     return ','.join(z + e for z,e in bits)
+
+def quick_latex(s):
+    str = s.replace('*',' ')
+    str = str.replace('(',r'\left(')
+    str = str.replace(')',r'\right)')
+    # multidigit exponents
+    str = re.sub(r'\^\s*(\d+)', r'^{\1}',str)
+    return '$'+str+'$'
+
+
 ############  Galois group object
 
 
@@ -248,6 +258,28 @@ def can_chartable(self):
             return False
         return self.wag.complex_characters_known
 
+    @lazy_attribute
+    def regulars(self):
+        t = list(db.gps_regular_polynomials.search({'label':self.label})) # it will be a short list
+        if t:
+            genknowl = display_knowl("gg.generic_polynomial", "generic")
+
+            def msg(code):
+                if code is None:
+                    return ''
+                if code == []:
+                    return f' is {genknowl} for any base field $K$'
+                if code == [0]:
+                    return fr' is {genknowl} for the base field $\Q$'
+                code = ','.join(str(z) for z in code)
+                return fr' is {genknowl} for any base field $K$ of characteristic $\neq$ {code}'
+
+            regdata= [(raw_typeset(z['polynomial'], quick_latex(z['polynomial'])), msg(z.get('generic'))) for z in t]
+            for j, (poly, msg) in enumerate(regdata):
+                if msg:
+                    regdata[j] = (poly, f'The polynomial $f_{{{j+1}}}$ {msg}')
+            return regdata
+
     def chartable(self):
         self.conjclasses # called to load info in self
         return render_template("character-table.html", gp=self,