Add example that demonstrates how to add/remove columns from the markdown table.

Author: alliepiper

README.md

@@ -73,6 +73,7 @@ various NVBench features and usecases:
 - [Reporting item/sec and byte/sec throughput statistics](examples/throughput.cu)
 - [Skipping benchmark configurations](examples/skip.cu)
 - [Benchmarking on a specific stream](examples/stream.cu)
+- [Adding / hiding columns (summaries) in markdown output](examples/summaries.cu)
 - [Benchmarks that sync CUDA devices: `nvbench::exec_tag::sync`](examples/exec_tag_sync.cu)
 - [Manual timing: `nvbench::exec_tag::timer`](examples/exec_tag_timer.cu)
 

examples/CMakeLists.txt

@@ -8,6 +8,7 @@ set(example_srcs
   exec_tag_timer.cu
   skip.cu
   stream.cu
+  summaries.cu
   throughput.cu
 )
 

examples/summaries.cu

@@ -0,0 +1,70 @@
+/*
+ *  Copyright 2025 NVIDIA Corporation
+ *
+ *  Licensed under the Apache License, Version 2.0 with the LLVM exception
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.
+ *
+ *  You may obtain a copy of the License at
+ *
+ *      http://llvm.org/foundation/relicensing/LICENSE.txt
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <nvbench/nvbench.cuh>
+
+// Grab some testing kernels from NVBench:
+#include <nvbench/test_kernels.cuh>
+
+// #define PRINT_DEFAULT_SUMMARY_TAGS
+
+void summary_example(nvbench::state &state)
+{
+  // Fetch parameters and compute duration in seconds:
+  const auto ms = static_cast<nvbench::float64_t>(state.get_int64("ms"));
+  const auto us = static_cast<nvbench::float64_t>(state.get_int64("us"));
+  const auto duration = ms * 1e-3 + us * 1e-6;
+
+  // Add a new column to the summary table with the derived duration used by the benchmark.
+  // See the documentation in nvbench/summary.cuh for more details.
+  {
+    nvbench::summary &summary = state.add_summary("duration");
+    summary.set_string("name", "Duration (s)");
+    summary.set_string("description", "The duration of the kernel execution.");
+    summary.set_string("hint", "duration");
+    summary.set_float64("value", duration);
+  }
+
+  // Run the measurements:
+  state.exec([duration](nvbench::launch &launch) {
+    nvbench::sleep_kernel<<<1, 1, 0, launch.get_stream()>>>(duration);
+  });
+
+#ifdef PRINT_DEFAULT_SUMMARY_TAGS
+  // The default summary tags can be found by inspecting the state after calling
+  // state.exec.
+  // They can also be found by looking at the json output (--json <filename>)
+  for (const auto &summary : state.get_summaries())
+  {
+    std::cout << summary.get_tag() << std::endl;
+  }
+#endif
+
+  // Default summary columns can be shown/hidden in the markdown output tables by adding/removing
+  // the "hide" key. Modify this benchmark to show the minimum and maximum times, but hide the
+  // means.
+  state.get_summary("nv/cold/time/gpu/min").remove_value("hide");
+  state.get_summary("nv/cold/time/gpu/max").remove_value("hide");
+  state.get_summary("nv/cold/time/gpu/mean").set_string("hide", "");
+  state.get_summary("nv/cold/time/cpu/min").remove_value("hide");
+  state.get_summary("nv/cold/time/cpu/max").remove_value("hide");
+  state.get_summary("nv/cold/time/cpu/mean").set_string("hide", "");
+}
+NVBENCH_BENCH(summary_example)
+  .add_int64_axis("ms", nvbench::range(10, 50, 20))
+  .add_int64_axis("us", nvbench::range(100, 500, 200));