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nu_command/matrix/
transpose.rs

1use crate::matrix::MatrixValue;
2use nu_engine::command_prelude::*;
3
4#[derive(Clone)]
5pub struct MatrixTranspose;
6
7impl Command for MatrixTranspose {
8    fn name(&self) -> &str {
9        "matrix transpose"
10    }
11
12    fn signature(&self) -> Signature {
13        Signature::build("matrix transpose")
14            .input_output_types(vec![(
15                Type::Custom("matrix".into()),
16                Type::Custom("matrix".into()),
17            )])
18            .category(Category::Filters)
19    }
20
21    fn description(&self) -> &str {
22        "Transpose a matrix (swap rows and columns). For n-dimensional arrays, reverses all axes."
23    }
24
25    fn search_terms(&self) -> Vec<&str> {
26        vec!["swap", "flip"]
27    }
28
29    fn run(
30        &self,
31        _engine_state: &EngineState,
32        _stack: &mut Stack,
33        call: &Call,
34        input: PipelineData,
35    ) -> Result<PipelineData, ShellError> {
36        let head = call.head;
37        let matrix = MatrixValue::from_value(&input.into_value(head)?)?;
38
39        let result = if matrix.array.ndim() == 2 {
40            matrix.array.t().to_owned()
41        } else {
42            let axes: Vec<usize> = (0..matrix.array.ndim()).rev().collect();
43            matrix.array.permuted_axes(ndarray::IxDyn(&axes)).to_owned()
44        };
45
46        Ok(MatrixValue::new(result)
47            .into_value(head)
48            .into_pipeline_data())
49    }
50
51    fn examples(&self) -> Vec<Example<'static>> {
52        vec![
53            Example {
54                description: "Transpose a 2x3 matrix to a 3x2 matrix",
55                example: "[[1 2 3] [4 5 6]] | into matrix | matrix transpose | matrix into-nu | to nuon",
56                result: Some(Value::test_string("[[1.0, 4.0], [2.0, 5.0], [3.0, 6.0]]")),
57            },
58            Example {
59                description: "Transpose an identity matrix (result is the same)",
60                example: "matrix identity 2 | matrix transpose | matrix into-nu | to nuon",
61                result: Some(Value::test_string("[[1.0, 0.0], [0.0, 1.0]]")),
62            },
63        ]
64    }
65}
66
67#[cfg(test)]
68mod test {
69    use super::*;
70
71    #[test]
72    fn test_examples() -> nu_test_support::Result {
73        nu_test_support::test().examples(MatrixTranspose)
74    }
75}