Cherry-pick [2.7] pin fastdigest==0.4.0 due to API changes (#4217)

docs/examples/federated_statistics_overview.rst

@@ -214,6 +214,14 @@ To calculate federated quantiles, we use the fastdigest package, which satisfies
 * Avoids transmitting large amounts of data
 * No system-level dependency
 
+Pin ``fastdigest`` to ``0.4.0``:
+
+.. code-block:: text
+
+    pip install fastdigest==0.4.0
+
+Newer ``fastdigest`` releases changed the TDigest API and are planned to be adopted in a later branch.
+
 The tdigest algorithm only carries the cluster coordinates, initially each data point is in its own cluster. By default, we compress with max_bin = sqrt(datasize) to compress the coordinates, so the data won't leak. You can always override max_bins if you prefer more or less compression.
 
 For detailed implementation instructions and configuration examples, please refer to the :github_nvflare_link:`Federated Statistics README <examples/advanced/federated-statistics/README.md>`.

docs/hello-world/hello-tabular-stats/index.rst

@@ -38,7 +38,7 @@ Install the dependency
 Install Optional Quantile Dependency -- fastdigest
 ------------------------------------------------------------
 
-If you intend to calculate quantiles, you need to install fastdigest.
+If you intend to calculate quantiles, install ``fastdigest==0.4.0``.
 
 Skip this step if you don't need quantile statistics.
 

examples/advanced/federated-statistics/df_stats/README.md

@@ -53,6 +53,12 @@ We chose the fastdigest Python package, a Rust-based package. The digest only ca
 initially, each data point is in its own cluster. By default, we will compress with max_bin = sqrt(datasize) 
 to compress the coordinates, so the data won't leak. You can always override max_bins if you prefer more or less compression.
 
+Install and pin:
+
+```bash
+pip install fastdigest==0.4.0
+```
+
 
 ## Configuration and Code
 

examples/hello-world/hello-tabular-stats/README.md

@@ -33,7 +33,7 @@ pip install -r requirements.txt
 
 ### Install Optional Quantile Dependency -- fastdigest
 
-If you intend to calculate quantiles, you need to install fastdigest. 
+If you intend to calculate quantiles, install `fastdigest==0.4.0`. 
 
 Skip this step if you don't need quantile statistics. 
 

examples/hello-world/hello-tabular-stats/df_stats.ipynb

@@ -86,7 +86,7 @@
    "source": [
     "## Install Optional Quantile Dependency – fastdigest\n",
     "\n",
-    "If you intend to calculate quantiles, you need to install fastdigest.\n",
+    "If you intend to calculate quantiles, install `fastdigest==0.4.0`.\n",
     "\n",
     "Skip this step if you don’t need quantile statistics.\n",
     "```\n",

examples/tutorials/self-paced-training/part-1_federated_learning_introduction/chapter-2_develop_federated_learning_applications/02.1_federated_statistics/federated_statistics_with_tabular_data/federated_statistics_with_tabular_data.ipynb

@@ -48,7 +48,7 @@
     "> Sidebar: \n",
     "> **Installing fastdigest**\n",
     ">\n",
-    "> If you intend to calculate quantiles, you need to install fastdigest.  the fastdigest not included in the requirements.txt file. If you are not calculating quantiles, you can skip this step.\n",
+    "> If you intend to calculate quantiles, install `fastdigest==0.4.0`.  the fastdigest not included in the requirements.txt file. If you are not calculating quantiles, you can skip this step.\n",
     ">\n",
     "> ```bash\n",
     "> pip install fastdigest==0.4.0\n",

setup.cfg

@@ -102,6 +102,7 @@ test_support =
 test =
     %(all)s
     %(test_support)s
+    fastdigest==0.4.0; python_version < "3.14"
 
 test_mac =
     %(all_mac)s