Support displaying 1D tensors (#5837)

### What

Technically two separate fixes:
* visualizability for 1 x n and n x 1 was blocked
* real single dimension tensors are now supported


Test code:

```py
import rerun as rr
import numpy as np

rr.init("1dtensor", spawn=True)
x = np.linspace(0.0, 100.0, 100)
rr.log("n", rr.Tensor(x))
rr.log("n_x_1", rr.Tensor(np.reshape(x, (100, 1))))
rr.log("1_x_n", rr.Tensor(np.reshape(x, (1, 100))))
```

Before:
<img width="1683" alt="Screenshot 2024-04-08 at 10 00 40"
src="https://github.com/rerun-io/rerun/assets/1220815/2f2850dd-2d17-40af-ab3b-d5b86fa20f04">
After first commit:
<img width="1698" alt="Screenshot 2024-04-08 at 10 02 53"
src="https://github.com/rerun-io/rerun/assets/1220815/ae4108f2-199e-4c92-9575-13d232146efd">

After second commit:


https://github.com/rerun-io/rerun/assets/1220815/18b3fc7a-c0d6-4fff-8d3d-ab7d26d5d2fe


### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[rerun.io/viewer](https://rerun.io/viewer/pr/5837)
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/5837?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/5837?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5837)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

CHANGELOG.md

@@ -108,6 +108,7 @@ Blueprints are currently only supported in the Python API, with C++ and Rust sup
 - Entity path query now shows simple statistics and warns if nothing is displayed [#5693](https://github.com/rerun-io/rerun/pull/5693)
 - Go back to example page with browser Back-button [#5750](https://github.com/rerun-io/rerun/pull/5750)
 - On Web, implement navigating back/forward with mouse buttons [#5792](https://github.com/rerun-io/rerun/pull/5792)
+- Support displaying 1D tensors [#5837](https://github.com/rerun-io/rerun/pull/5837)
 
 #### 🧑‍🏫 Examples
 - New `incremental_logging` example [#5462](https://github.com/rerun-io/rerun/pull/5462)

crates/re_space_view_bar_chart/src/space_view_class.rs

@@ -4,8 +4,9 @@ use re_log_types::EntityPath;
 use re_space_view::{controls, suggest_space_view_for_each_entity};
 use re_types::datatypes::TensorBuffer;
 use re_viewer_context::{
-    auto_color, SpaceViewClass, SpaceViewClassIdentifier, SpaceViewClassRegistryError, SpaceViewId,
-    SpaceViewState, SpaceViewSystemExecutionError, ViewQuery, ViewerContext,
+    auto_color, IdentifiedViewSystem as _, IndicatedEntities, PerVisualizer, SpaceViewClass,
+    SpaceViewClassIdentifier, SpaceViewClassRegistryError, SpaceViewId, SpaceViewState,
+    SpaceViewSystemExecutionError, ViewQuery, ViewerContext, VisualizableEntities,
 };
 
 use super::visualizer_system::BarChartVisualizerSystem;
@@ -66,6 +67,27 @@ impl SpaceViewClass for BarChartSpaceView {
         None
     }
 
+    fn choose_default_visualizers(
+        &self,
+        entity_path: &EntityPath,
+        visualizable_entities_per_visualizer: &PerVisualizer<VisualizableEntities>,
+        _indicated_entities_per_visualizer: &PerVisualizer<IndicatedEntities>,
+    ) -> re_viewer_context::SmallVisualizerSet {
+        // Default implementation would not suggest the BarChart visualizer for tensors and 1D images,
+        // since they're not indicated with a BarChart indicator.
+        // (and as of writing, something needs to be both visualizable and indicated to be shown in a visualizer)
+
+        // Keeping this implementation simple: We know there's only a single visualizer here.
+        if visualizable_entities_per_visualizer
+            .get(&BarChartVisualizerSystem::identifier())
+            .map_or(false, |entities| entities.contains(entity_path))
+        {
+            std::iter::once(BarChartVisualizerSystem::identifier()).collect()
+        } else {
+            Default::default()
+        }
+    }
+
     fn spawn_heuristics(
         &self,
         ctx: &ViewerContext<'_>,

crates/re_space_view_tensor/src/dimension_mapping.rs

@@ -45,8 +45,8 @@ impl DimensionMapping {
             },
 
             1 => DimensionMapping {
-                selectors: vec![DimensionSelector::new(0)],
-                width: None,
+                selectors: Default::default(),
+                width: Some(0),
                 height: None,
                 invert_width: false,
                 invert_height: false,

crates/re_space_view_tensor/src/space_view_class.rs

@@ -565,18 +565,37 @@ pub fn selected_tensor_slice<'a, T: Copy>(
 
     assert!(dimension_mapping.is_valid(tensor.ndim()));
 
-    // TODO(andreas) - shouldn't just give up here
-    if dimension_mapping.width.is_none() || dimension_mapping.height.is_none() {
-        return tensor.view();
-    }
+    let (width, height) =
+        if let (Some(width), Some(height)) = (dimension_mapping.width, dimension_mapping.height) {
+            (width, height)
+        } else if let Some(width) = dimension_mapping.width {
+            // If height is missing, create a 1D row.
+            (width, 1)
+        } else if let Some(height) = dimension_mapping.height {
+            // If width is missing, create a 1D column.
+            (1, height)
+        } else {
+            // If both are missing, give up.
+            return tensor.view();
+        };
+
+    let view = if tensor.shape().len() == 1 {
+        // We want 2D slices, so for "pure" 1D tensors add a dimension.
+        // This is important for above width/height conversion to work since this assumes at least 2 dimensions.
+        tensor
+            .view()
+            .into_shape(ndarray::IxDyn(&[tensor.len(), 1]))
+            .unwrap()
+    } else {
+        tensor.view()
+    };
 
-    let axis = dimension_mapping
-        .height
+    #[allow(clippy::tuple_array_conversions)]
+    let axis = [height, width]
         .into_iter()
-        .chain(dimension_mapping.width)
         .chain(dimension_mapping.selectors.iter().map(|s| s.dim_idx))
         .collect::<Vec<_>>();
-    let mut slice = tensor.view().permuted_axes(axis);
+    let mut slice = view.permuted_axes(axis);
 
     for DimensionSelector { dim_idx, .. } in &dimension_mapping.selectors {
         let selector_value = selector_values.get(dim_idx).copied().unwrap_or_default() as usize;

crates/re_space_view_tensor/src/visualizer_system.rs

@@ -1,12 +1,10 @@
 use re_data_store::{LatestAtQuery, VersionedComponent};
 use re_entity_db::EntityPath;
 use re_log_types::RowId;
-use re_space_view::diff_component_filter;
 use re_types::{archetypes::Tensor, components::TensorData, tensor_data::DecodedTensor};
 use re_viewer_context::{
     IdentifiedViewSystem, SpaceViewSystemExecutionError, TensorDecodeCache, ViewContextCollection,
-    ViewQuery, ViewerContext, VisualizerAdditionalApplicabilityFilter, VisualizerQueryInfo,
-    VisualizerSystem,
+    ViewQuery, ViewerContext, VisualizerQueryInfo, VisualizerSystem,
 };
 
 #[derive(Default)]
@@ -20,25 +18,11 @@ impl IdentifiedViewSystem for TensorSystem {
     }
 }
 
-struct TensorVisualizerEntityFilter;
-
-impl VisualizerAdditionalApplicabilityFilter for TensorVisualizerEntityFilter {
-    fn update_applicability(&mut self, event: &re_data_store::StoreEvent) -> bool {
-        diff_component_filter(event, |tensor: &re_types::components::TensorData| {
-            !tensor.is_vector()
-        })
-    }
-}
-
 impl VisualizerSystem for TensorSystem {
     fn visualizer_query_info(&self) -> VisualizerQueryInfo {
         VisualizerQueryInfo::from_archetype::<Tensor>()
     }
 
-    fn applicability_filter(&self) -> Option<Box<dyn VisualizerAdditionalApplicabilityFilter>> {
-        Some(Box::new(TensorVisualizerEntityFilter))
-    }
-
     fn execute(
         &mut self,
         ctx: &ViewerContext<'_>,

tests/python/release_checklist/check_1d_tensor_data.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import os
+from argparse import Namespace
+from uuid import uuid4
+
+import numpy as np
+import rerun as rr
+
+README = """
+# 1D Image/Tensor/BarChart
+
+This checks the different ways 1D arrays can be visualized.
+
+### Actions
+
+You should see:
+* a tensor view with 1D data
+* an image view with a 1D image
+* a bar chart
+
+Bonus actions:
+* use the ui to create a tensor/bar-chart with each of the entities no matter how it was logged
+    * TODO(#5847): Right now tensors & bar charts can not be reinterpreted as 2D images.
+      In this example, image is correctly not suggested for the `tensor` and `image` entities,
+      since they are of 1D shape, but this would be relevant if they were 1xN or Nx1.
+
+"""
+
+
+def log_readme() -> None:
+    rr.log("readme", rr.TextDocument(README, media_type=rr.MediaType.MARKDOWN), timeless=True)
+
+
+def log_1d_data() -> None:
+    x = np.linspace(0.0, 100.0, 100)
+    rr.log("tensor", rr.Tensor(x))
+    rr.log("barchart", rr.BarChart(x))
+    # We're not allowing "real" 1D here and force users to be explicit about width/height
+    rr.log("image", rr.Image(np.reshape(x, (1, 100))))
+
+
+def run(args: Namespace) -> None:
+    rr.script_setup(args, f"{os.path.basename(__file__)}", recording_id=uuid4())
+
+    log_readme()
+    log_1d_data()
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(description="Interactive release checklist")
+    rr.script_add_args(parser)
+    args = parser.parse_args()
+    run(args)