nu-command 0.115.1

Nushell's built-in commands
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

use crate::matrix::MatrixValue;
use crate::matrix::value::values_to_f64s;
use nu_engine::command_prelude::*;

#[derive(Clone)]
pub struct MatrixSetCol;

impl Command for MatrixSetCol {
    fn name(&self) -> &str {
        "matrix set-col"
    }

    fn signature(&self) -> Signature {
        Signature::build("matrix set-col")
            .input_output_types(vec![(
                Type::Custom("matrix".into()),
                Type::Custom("matrix".into()),
            )])
            .required(
                "index",
                SyntaxShape::Int,
                "The column index to replace (0-based).",
            )
            .required(
                "replacement",
                SyntaxShape::List(Box::new(SyntaxShape::Number)),
                "The new column values as a list of numbers.",
            )
            .category(Category::Filters)
    }

    fn description(&self) -> &str {
        "Replace a column in a 2D matrix."
    }

    fn search_terms(&self) -> Vec<&str> {
        vec!["column", "replace"]
    }

    fn run(
        &self,
        engine_state: &EngineState,
        stack: &mut Stack,
        call: &Call,
        input: PipelineData,
    ) -> Result<PipelineData, ShellError> {
        let head = call.head;
        let index: usize = call.req::<i64>(engine_state, stack, 0)? as usize;
        let replacement: Value = call.req(engine_state, stack, 1)?;
        let matrix = MatrixValue::from_value(&input.into_value(head)?)?;

        if matrix.array.ndim() != 2 {
            return Err(ShellError::Generic(
                nu_protocol::shell_error::generic::GenericError::new(
                    "Invalid dimensions",
                    format!(
                        "set-col requires a 2D matrix, got {} dimensions",
                        matrix.array.ndim()
                    ),
                    head,
                ),
            ));
        }

        let replacement_vals = match replacement {
            Value::List { vals, .. } => vals,
            _ => {
                return Err(ShellError::Generic(
                    nu_protocol::shell_error::generic::GenericError::new(
                        "Invalid replacement",
                        "expected a list of numbers",
                        head,
                    ),
                ));
            }
        };

        let nrows = matrix.array.shape()[0];
        let ncols = matrix.array.shape()[1];

        if replacement_vals.len() != nrows {
            return Err(ShellError::Generic(
                nu_protocol::shell_error::generic::GenericError::new(
                    "Size mismatch",
                    format!(
                        "replacement has {} elements, but column has {} rows",
                        replacement_vals.len(),
                        nrows
                    ),
                    head,
                ),
            ));
        }

        if index >= ncols {
            return Err(ShellError::Generic(
                nu_protocol::shell_error::generic::GenericError::new(
                    "Index out of bounds",
                    format!(
                        "column index {} is out of bounds, matrix has {} columns",
                        index, ncols
                    ),
                    head,
                ),
            ));
        }

        let floats = values_to_f64s(&replacement_vals, head)?;

        let mut new_array = matrix.array;
        for (i, &val) in floats.iter().enumerate() {
            new_array[[i, index]] = val;
        }

        Ok(MatrixValue::new(new_array)
            .into_value(head)
            .into_pipeline_data())
    }

    fn examples(&self) -> Vec<Example<'static>> {
        vec![
            Example {
                description: "Replace the first column of a 2x3 matrix",
                example: "matrix zeros 2 3 | matrix set-col 0 [1.0 2.0] | matrix into-nu | to nuon",
                result: Some(Value::test_string("[[1.0, 0.0, 0.0], [2.0, 0.0, 0.0]]")),
            },
            Example {
                description: "Replace the second column of a 2x2 matrix",
                example: "matrix zeros 2 2 | matrix set-col 1 [4.0 5.0] | matrix into-nu | to nuon",
                result: Some(Value::test_string("[[0.0, 4.0], [0.0, 5.0]]")),
            },
        ]
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn test_examples() -> nu_test_support::Result {
        nu_test_support::test().examples(MatrixSetCol)
    }
}