LMFDB · May 29, 2026 · Mar 11, 2026 · Mar 11, 2026 · Mar 15, 2026 · Mar 15, 2026
diff --git a/.gitignore b/.gitignore
@@ -37,10 +37,9 @@ LMFDBinventory.log
 LMFDBtransactions_inv.log
 
 scripts/groups/Make-images/images/*.png
-scripts/groups/Make-images/images/eqguts.tex
-scripts/groups/Make-images/prettyindex
-scripts/groups/Make-images/imagereloader
 
 smf_lmfdb
 __pycache__
-create_input_data.py
+scripts/groups/Make-images/images/eqguts.tex
+scripts/groups/Make-images/prettyindex
+scripts/groups/Make-images/imagereloader
diff --git a/Development.md b/Development.md
@@ -39,8 +39,7 @@ Structural Conventions
 
 Below, we describe several of the structural conventions used in the LMFDB. Note
 that we also have styling conventions for the content of individual pages. These
-styling conventions are described in
-[StyleGuide.md](https://github.com/LMFDB/lmfdb/blob/main/StyleGuide.md).
+styling conventions are described in [StyleGuide.md](./StyleGuide.md).
 
 Pages in the LMFDB
 ------------------
@@ -206,11 +205,11 @@ should be
 Here and throughout this document, we say "should" instead of "must", with
 the understanding that some compromises will be inevitable.
 
-Here are some principles:
+Here are some conventions the LMFDB uses:
 
 1. If X is the URL of an object, then L/X is the URL of its standard
    L-function. According to the Langlands program, other L-functions
-   associated to X have the form L(s, X, rho). Examples include
+   associated to X may be written on the the form L(s, X, rho). Examples include
 
    - L(s, f, sym^2)
    - L(s, f, spin)
@@ -261,8 +260,7 @@ Here are some principles:
    should be considered permanent:
 
    - `/ArtinRepresentation/\<dim>/\<conductor>/\<label>`
-   - `/Character/Dirichlet/\<modulus>/\<number>`
-   - `/Character/Hecke/\<number_field>/\<modulus>/\<number>`
+   - `/Character/Dirichlet/\<modulus>/\<label>`
    - `/EllipticCurve/Q/\<label>`
    - `/GaloisGroup/\<label>`
    - `/padicField/\<label>`
@@ -356,9 +354,9 @@ Testing
 
 - A code coverage diagnostic can be obtained via
   ```
-  ./test.sh html
+  ./test.sh coverage
   ```
-  it produces beautiful coverage scores in `lmfdb/cover/index.html`
+  which produces coverage scores saved in `lmfdb/htmlcov`.
 
 Code Snippets 
 -------------
@@ -413,105 +411,54 @@ The tag `langs` here is optional, and if omitted, all (available) languages in t
 
 Part of the code snippet testing system is a pair of code actions to generate evaluation log files automatically. The first one runs when a change to a `code*.yaml` file is pulled to the main branch, and if so, regenerates the evaluation files. If the output is different from the previous evaluation files, it will make a pull request, allowing you to manually check that the output is as expected. The logic is in `.github/workflows/snippet_generate.yml`.
 
-Additionally, there's a second CI which runs twice a month and checks that the evaluations are consistent - it can also be run on demand. This ensures that if and when SageMath (or another CAS) deprecates a function, we'll know without having to wait for someone to update the yaml files, rerun the code or submit a bug report. If this action generates a different output than what's stored in the evaluation files, it will error, and upload the diff as an artifact. This is in `.github/workflows/snippet_test.yml`. Furthermore, it will create/update an issue (see https://github.com/LMFDB/lmfdb/issues/6810 for example) which keeps track of all the evaluation errors.
+Additionally, there's a second CI action which runs twice a month and checks that the evaluations are consistent - it can also be run on demand. This ensures that if and when SageMath (or another CAS) deprecates a function, we'll know without having to wait for someone to update the yaml files, rerun the code or submit a bug report. If this action generates a different output than what's stored in the evaluation files, it will error, and upload the diff as an artifact. This is in `.github/workflows/snippet_test.yml`. Furthermore, it will create/update an issue (see https://github.com/LMFDB/lmfdb/issues/6810 for example) which keeps track of all the evaluation errors.
 
 
 Pro Tip: Debugging
 -------------------
 
-Just add
+Adding
 ```
   import pdb; pdb.set_trace()
 ```
-somewhere (e.g. protected inside a sensible if) this magic
-line and you will end up inside the interactive python
-debugger. there, you can check for the local variables with dir()
-you can execute python code (e.g. to introspect objects)
-and use "pp <var name>" to pretty print variables and
-to continue executing code use the "n" command.
-When you get lost, the command "bt" shows you exactly where you
-are and "up" helps you to get on step up on the stack.
-Of course, "help `<command>`" will tell you more...
+somewhere in a python file (e.g. protected inside a sensible if) will pause the execution of the program; 
+this puts you inside an interactive python debugger, where you can:
 
-Git Tips
-=========
-
-global .gitignore
------------------
-
-Please configure Git to have a global .gitignore for all your projects.
-It should contain all the files which are not project specific, but happen
-on your machine. E.g. temporary files ending in `...~` or `.DS_store`.
+- check for the local variables with `dir()`, 
+- you can execute arbitrary python code (e.g. to inspect objects),
+- use `pp <var name>` to pretty print variables,
+- continue executing code using the `n` command.
 
-[copy paste ready instructions on github](https://help.github.com/articles/ignoring-files#global-gitignore)
+If you get lost, the command `bt` shows you exactly where you
+are, and `up` helps you to get on step up on the stack.
+Of course, `help <command>` will tell you more.
 
-.gitconfig
-----------
-
-In your home directory, in the file ~/.gitconfig
+Git Tips
+=========
 
-```
+Contributing to the LMFDB requires some familiarity with git, a popular version control system which LMFDB uses. The LMFDB code base is hosted on Github, which is a common hosting service owned by Microsoft.
+- [Official git tutorial](https://git-scm.com/docs/gittutorial) and [Github's git guide](https://github.com/git-guides)
+- Use a global .gitignore file to exclude temporary files like `.DS_store` or `main.py~`; [copy-paste ready instructions on github](https://help.github.com/articles/ignoring-files#global-gitignore).
+- Configure your global .gitconfig for shortcuts or global configuration options; for example:
+  ```
 [alias]
-        st=status
-        aliases=!git config --get-regexp 'alias.*' | colrm 1 6 | sed 's/[ ]/ = /'
-        ci=commit
-        br=branch
-        co=checkout
-        df=diff
-        who=shortlog -s --
-        ll = log --oneline --graph --decorate -25
-        lla = log --oneline --graph --decorate --all -25
-        wdiff=diff --word-diff=color
+		st=status
+		aliases=!git config --get-regexp 'alias.*' | colrm 1 6 | sed 's/[ ]/ = /'
+		ci=commit
+		br=branch
+		co=checkout
+		df=diff
+		who=shortlog -s --
+		ll = log --oneline --graph --decorate -25
+		lla = log --oneline --graph --decorate --all -25
+		wdiff=diff --word-diff=color
 [color]
-    ui = auto
-    branch = auto
-    diff = auto
-    interactive = auto
-    status = auto
-```
-
-List-table should always be like
---------------------------------
-
-```
-<table class="ntdata">
-  <thead><tr><td>...</td></tr></thead>
-
-  <tbody>
-   <tr class="odd"> <td>...</td></tr>
-   <tr class="even"><td>...</td></tr>
-   <tr class="odd"> <td>...</td></tr>
-   ...
-  </tbody>
-</table>
-```
-
-... we might also switch to CSS3's nth-element selector and forget about this.
-
-
-Properties
-----------
-
-The table on the right renders Strings formatted in the following datastructure:
-
-```
-prop = [ ( '<description>', [ '<value 1>', '<value 2>', ...] ), ... ]
-```
-
-or
-
-```
-prop = [ ( '<description>', '<value>'), ('<description>', '<value>'), ... ]
-```
-
-you can mix list or non-list.
-
-
-LaTeX Macros
-------------
-
-Latex macros are documented in a knowl that will appear when you start editing one.
-
+	ui = auto
+	branch = auto
+	diff = auto
+	interactive = auto
+	status = auto
+	```
 
 Server Hook
 -----------

diff --git a/lmfdb/api/api.py b/lmfdb/api/api.py
@@ -316,6 +316,8 @@ def apierror(msg, flash_extras=[], code=404, table=True):
     next_req = dict(request.args)
     next_req["_offset"] = offset
     url_args = next_req.copy()
+    # Remove _format so that we don't specify that keyword twice
+    url_args.pop("_format", None)
     query = url_for(".api_query", table=table, **next_req)
     offset += len(data)
     next_req["_offset"] = offset
@@ -368,7 +370,7 @@ def apierror(msg, flash_extras=[], code=404, table=True):
 
 
 # This function is used to show the data associated to a given homepage, which could possibly be from multiple tables.
-def datapage(labels, tables, title, bread, label_cols=None, sorts=None):
+def datapage(labels, tables, title, bread, label_cols=None, sorts=None, limit=100):
     """
     INPUT:
 
@@ -378,8 +380,15 @@ def datapage(labels, tables, title, bread, label_cols=None, sorts=None):
     - ``bread`` -- bread for the page
     - ``label_cols`` -- a list of column names of the same length; defaults to using ``label`` everywhere
     - ``sorts`` -- lists for sorting each table; defaults to None
+    - ``limit`` -- maximum number of rows displayed from each table; if more rows match, the total count is reported instead of listing them all
     """
     format = request.args.get("_format", "html")
+    try:
+        limit_arg = request.args.get("_limit")
+        if limit_arg is not None:
+            limit = max(0, min(10000, int(limit_arg)))
+    except (TypeError, ValueError):
+        pass
     if not isinstance(tables, list):
         tables = [tables]
     if not isinstance(labels, list):
@@ -400,6 +409,7 @@ def apierror(msg, flash_extras=[], code=404, table=False):
         else:
             return abort(code, msg % tuple(flash_extras))
     data = []
+    totals = []
     search_schema = {}
     extra_schema = {}
     for label, table, col, sort in zip(labels, tables, label_cols, sorts):
@@ -409,7 +419,15 @@ def apierror(msg, flash_extras=[], code=404, table=False):
             q = {col: label}
         coll = db[table]
         try:
-            data.append(list(coll.search(q, projection=3, sort=sort)))
+            # Fetch limit+1 rows to cheaply detect truncation; only call count() if we actually exceeded the limit.
+            rows = list(coll.search(q, projection=3, sort=sort, limit=limit + 1))
+            if len(rows) > limit:
+                total = coll.count(q)
+                rows = rows[:limit]
+            else:
+                total = len(rows)
+            data.append(rows)
+            totals.append(total)
         except QueryCanceledError:
             return apierror("Query %s exceeded time limit.", [q], code=500, table=table)
         except KeyError as err:
@@ -429,6 +447,8 @@ def apierror(msg, flash_extras=[], code=404, table=False):
         "label_cols": label_cols,
         "timestamp": utc_now_naive().isoformat(),
         "data": data,
+        "totals": totals,
+        "limit": limit,
     }
     if format.lower() == "json":
         return current_app.response_class(json.dumps(data, indent=2), mimetype='application/json')

diff --git a/lmfdb/api/templates/apidata.html b/lmfdb/api/templates/apidata.html
@@ -23,15 +23,18 @@
 </div>
 
 <ul class="api-entries">
-  {% for table, recs, label, label_col in zip(tables, data, labels, label_cols) %}
+  {% for table, recs, label, label_col, total in zip(tables, data, labels, label_cols, totals) %}
     <li>
-      {% if (recs|length) == 0 %}
+      {% if total == 0 %}
         {{ label_col }} {{ label }} does not appear in <a href="{{ url_for('API.api_query', table=table) }}">{{ table }}</a>
-      {% elif (recs|length) == 1 %}
+      {% elif total == 1 %}
         <a href="{{ url_for('API.api_query_id', table=table, id=recs[0].get('id')) }}">{{ table }}</a> &bull; {% include "apischema.html" %} </br/>
         <code>{{ pretty(recs[0], id=False) }}</code>
       {% else %}
         <a href="{{ url_for('API.api_query', table=table) }}">{{ table }}</a> &bull; {% include "apischema.html" %} </br/>
+        {% if (recs|length) < total %}
+          Showing the first {{ recs|length }} of {{ total }} matching records in this table.
+        {% endif %}
         <ul>
           {% for entry in recs %}
             <li>

diff --git a/lmfdb/belyi/templates/belyi_galmap.html b/lmfdb/belyi/templates/belyi_galmap.html
@@ -5,6 +5,7 @@
   .toggle {margin-top:5px; margin-left:20px;}
   div.properties-body table tr td.label { vertical-align: top    ; }
   #content > h2.subhead { color:{{color.black}};}
+  #dessin-box svg { width: 100%; height: auto; display: block; }
 </style>
 
 <script>
@@ -14,6 +15,22 @@
     $('.plane_eqn').css("display", "none");
     $('.'+eqnstyle).css("display", "inline");
   }
+
+var _activeDessinRow = null;
+function viewEmbedding(idx) {
+  var $box = $('#dessin-box');
+  if (_activeDessinRow === idx) {
+    $box.hide();
+    _activeDessinRow = null;
+    return false;
+  }
+  $('.dessin-svg-item').hide();
+  $('#dessin-svg-' + idx).show();
+  $box.show();
+  $box[0].scrollIntoView({behavior: 'smooth', block: 'nearest'});
+  _activeDessinRow = idx;
+  return false;
+}
 </script>
 
 <h2>{{ KNOWL('belyi.base_field', title='Base field')}}</h2>
@@ -107,20 +124,39 @@ <h2>{{ KNOWL('nf.embedding', title="Embeddings") }}</h2>
       <tr>
         <td>Embedding $\nu \mapsto \nu_i \in \mathbb{C}$</td>
         <td>{{ KNOWL('belyi.permutation_triple', title="Permutation triple") }}</td>
+        {% if data.dessin_svgs %}<td>Dessin</td>{% endif %}
       </tr>
     </thead>
     <tbody>
       {% for g in data.embeddings_and_triples %}
-       <td>${{g['embedding']}}$</td>
-       <td>${{g['triple']}}$</td>
-       </tr>
-      <!-- TODO: uncomment this when embedded map pages are reactivated
-         <td><a href="{{g['triple_link']}}">${{g['embedding']}}$</a></td>
-         <td><a href="{{g['triple_link']}}">${{g['triple']}}$</a></td>
-         </tr>
-      -->
+      <tr>
+        <td>${{g['embedding']}}$</td>
+        <td>${{g['triple']}}$</td>
+        {% if data.dessin_svgs %}
+        <td><a href="#" onclick="return viewEmbedding({{ loop.index0 }});">View Embedding</a></td>
+        {% endif %}
+      </tr>
       {% endfor %}
     </tbody>
-    </table>
+  </table>
+
+{% if data.dessin_svgs %}
+  <div id="dessin-box" class="knowl-output" style="display:none; max-width:440px;">
+    <div class="knowl"><div><div class="knowl-content">
+      <strong>Dessin d&rsquo;enfant</strong>
+      {% for g in data.embeddings_and_triples %}
+        {% set svg_idx = loop.index0 if loop.index0 < data.dessin_svgs|length else 0 %}
+        <div id="dessin-svg-{{ loop.index0 }}" class="dessin-svg-item" style="display:none;">
+          {{ data.dessin_svgs[svg_idx]|safe }}
+        </div>
+      {% endfor %}
+      <p style="font-size:0.85em; margin-top:0.75em;">
+        The drawing routine is based on a C program by Gunnar Brinkmann, described in:<br>
+        G. Brinkmann, <em>Drawing maps on oriented surfaces</em>, 2025.
+        Preprint: <a href="https://arxiv.org/abs/2505.01480">arXiv:2505.01480</a>.
+      </p>
+    </div></div></div>
+  </div>
+{% endif %}
 
 {% endblock %}