logo
  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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
#[doc(hidden)]
use ndarray::prelude::*;
use ndarray::{Data, ShapeBuilder};

use crate::prelude::dim_symbol;
use crate::*;

impl<'a, T> FromRobj<'a> for ArrayView1<'a, T>
where
    Robj: AsTypedSlice<'a, T>,
{
    /// Convert an R object to a `ndarray` ArrayView1.
    fn from_robj(robj: &'a Robj) -> std::result::Result<Self, &'static str> {
        if let Some(v) = robj.as_typed_slice() {
            Ok(ArrayView1::<'a, T>::from(v))
        } else {
            Err("Not a vector of the correct type.")
        }
    }
}

macro_rules! make_array_view_2 {
    ($type: ty, $error_str: expr) => {
        impl<'a> FromRobj<'a> for ArrayView2<'a, $type> {
            /// Convert an R object to a `ndarray` ArrayView2.
            fn from_robj(robj: &'a Robj) -> std::result::Result<Self, &'static str> {
                if robj.is_matrix() {
                    let nrows = robj.nrows();
                    let ncols = robj.ncols();
                    if let Some(v) = robj.as_typed_slice() {
                        // use fortran order.
                        let shape = (nrows, ncols).into_shape().f();
                        if let Ok(res) = ArrayView2::from_shape(shape, v) {
                            return Ok(res);
                        }
                    }
                }
                return Err($error_str);
            }
        }
    };
}

make_array_view_2!(Rbool, "Not a logical matrix.");
make_array_view_2!(i32, "Not an integer matrix.");
make_array_view_2!(f64, "Not a floating point matrix.");
//make_array_view_2!(u8, "Not a raw matrix.");

// impl<'a, T> From<ArrayView2<'a, T>> for Robj
// where
//     T : ToVectorValue
// {
//     fn from(array: ArrayView2<T>) -> Self {
//         let dims = array.dim();
//         let slice : &[T] = array.as_slice().unwrap();
//         let mx = Matrix::new(slice, dims.0, dims.1);
//         r!(mx)
//     }
// }
impl<A, S, D> TryFrom<&ArrayBase<S, D>> for Robj
where
    S: Data<Elem = A>,
    A: Copy + ToVectorValue,
    D: Dimension,
{
    type Error = Error;

    fn try_from(value: &ArrayBase<S, D>) -> Result<Self> {
        // Refer to https://github.com/rust-ndarray/ndarray/issues/1060 for an excellent discussion
        // on how to convert from `ndarray` types to R/fortran arrays
        // This thread has informed the design decisions made here.

        // In general, transposing and then iterating an ndarray in C-order (`iter()`) is exactly
        // equivalent to iterating that same array in Fortan-order (which `ndarray` doesn't currently support)
        value
            .t()
            .iter()
            // Since we only have a reference, we have to copy all elements so that we can own the entire R array
            .copied()
            .collect_robj()
            .set_attrib(
                dim_symbol(),
                value
                    .shape()
                    .iter()
                    .map(|x| i32::try_from(*x))
                    .collect::<std::result::Result<Vec<i32>, <i32 as TryFrom<usize>>::Error>>()
                    .map_err(|_err| {
                        Error::Other(String::from(
                            "One or more array dimensions were too large to be handled by R.",
                        ))
                    })?,
            )
    }
}

#[test]
fn test_from_robj() {
    test! {
        assert_eq!(
            <ArrayView1<f64>>::from_robj(&Robj::from(1.)),
            Ok(ArrayView1::<f64>::from(&[1.][..]))
        );
        assert_eq!(
            <ArrayView1<i32>>::from_robj(&Robj::from(1)),
            Ok(ArrayView1::<i32>::from(&[1][..]))
        );
        assert_eq!(
            <ArrayView1<Rbool>>::from_robj(&Robj::from(true)),
            Ok(ArrayView1::<Rbool>::from(&[TRUE][..]))
        );

        let robj = R!("matrix(c(1, 2, 3, 4, 5, 6, 7, 8), ncol=2, nrow=4)")?;
        let mx = <ArrayView2<f64>>::from_robj(&robj)?;
        assert_eq!(mx[[0, 0]], 1.0);
        assert_eq!(mx[[1, 0]], 2.0);
        assert_eq!(mx[[2, 0]], 3.0);
        assert_eq!(mx[[3, 0]], 4.0);
        assert_eq!(mx[[0, 1]], 5.0);
        assert_eq!(mx[[1, 1]], 6.0);
        assert_eq!(mx[[2, 1]], 7.0);
        assert_eq!(mx[[3, 1]], 8.0);

        // check basic logic of fortran-order matrices.
        let col0 = mx.column(0);
        assert_eq!(col0[0], 1.0);
        assert_eq!(col0[1], 2.0);
        assert_eq!(col0[2], 3.0);
        assert_eq!(col0[3], 4.0);

        // check integer matrices
        let robj = R!("matrix(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L), ncol=2, nrow=4)")?;
        let mx = <ArrayView2<i32>>::from_robj(&robj)?;
        assert_eq!(mx[[0, 0]], 1);
        assert_eq!(mx[[1, 0]], 2);
        assert_eq!(mx[[2, 0]], 3);
        assert_eq!(mx[[3, 0]], 4);
        assert_eq!(mx[[0, 1]], 5);
        assert_eq!(mx[[1, 1]], 6);
        assert_eq!(mx[[2, 1]], 7);
        assert_eq!(mx[[3, 1]], 8);

        // check logical matrices
        let robj = R!("matrix(c(T, T, T, T, F, F, F, F), ncol=2, nrow=4)")?;
        let mx = <ArrayView2<Rbool>>::from_robj(&robj)?;
        assert_eq!(mx[[0, 0]], TRUE);
        assert_eq!(mx[[1, 0]], TRUE);
        assert_eq!(mx[[2, 0]], TRUE);
        assert_eq!(mx[[3, 0]], TRUE);
        assert_eq!(mx[[0, 1]], FALSE);
        assert_eq!(mx[[1, 1]], FALSE);
        assert_eq!(mx[[2, 1]], FALSE);
        assert_eq!(mx[[3, 1]], FALSE);

        // check raw matrices
        // let robj = r!(Matrix::new(vec![1_u8, 2, 3, 4, 5, 6, 7, 8], 4, 2));
        // let mx = <ArrayView2<u8>>::from_robj(&robj)?;
        // assert_eq!(mx[[0, 0]], 1);
        // assert_eq!(mx[[1, 0]], 2);
        // assert_eq!(mx[[2, 0]], 3);
        // assert_eq!(mx[[3, 0]], 4);
        // assert_eq!(mx[[0, 1]], 5);
        // assert_eq!(mx[[1, 1]], 6);
        // assert_eq!(mx[[2, 1]], 7);
        // assert_eq!(mx[[3, 1]], 8);
    }
}

#[test]
fn test_to_robj() {
    test! {
        // An empty array should still convert to an empty R array with the same shape
        assert_eq!(
            &Robj::try_from(&Array4::<i32>::zeros((0, 1, 2, 3).f()))?,
            &R!("array(integer(), c(0, 1, 2, 3))")?
        );

        assert_eq!(
            &Robj::try_from(&array![1., 2., 3.])?,
            &R!("array(c(1, 2, 3))")?
        );

        // We give both R and Rust the same 1d vector and tell them both to read it as a matrix
        // in C order. Therefore these arrays should be the same.
        assert_eq!(
            &Robj::try_from(&Array::from_shape_vec((2, 3), vec![1., 2., 3., 4., 5., 6.]).unwrap())?,
            &R!("matrix(c(1, 2, 3, 4, 5, 6), nrow=2, byrow=TRUE)")?
        );

        // We give both R and Rust the same 1d vector and tell them both to read it as a matrix
        // in fortran order. Therefore these arrays should be the same.
        assert_eq!(
            &Robj::try_from(&Array::from_shape_vec((2, 3).f(), vec![1., 2., 3., 4., 5., 6.]).unwrap())?,
            &R!("matrix(c(1, 2, 3, 4, 5, 6), nrow=2, byrow=FALSE)")?
        );

        // We give both R and Rust the same 1d vector and tell them both to read it as a 3d array
        // in fortran order. Therefore these arrays should be the same.
        assert_eq!(
            &Robj::try_from(&Array::from_shape_vec((1, 2, 3).f(), vec![1, 2, 3, 4, 5, 6]).unwrap())?,
            &R!("array(1:6, c(1, 2, 3))")?
        );


        // We give R a 1d vector and tell it to read it as a 3d vector
        // Then we give Rust the equivalent vector manually split out.
        assert_eq!(
            &Robj::try_from(&array![[[1, 5], [3, 7]], [[2, 6], [4, 8]]])?,
            &R!("array(1:8, dim=c(2, 2, 2))")?
        );
    }
}

#[test]
fn test_round_trip() {
    test! {
        let rvals = [
            R!("matrix(c(1L, 2L, 3L, 4L, 5L, 6L), nrow=2)"),
            R!("array(1:8, c(4, 2))")
        ];
        for rval in rvals {
            let rval = rval.unwrap();
            let rust_arr= <ArrayView2<i32>>::from_robj(&rval).unwrap();
            let r_arr: Robj = (&rust_arr).try_into().unwrap();
            assert_eq!(
                rval,
                r_arr
            );
        }
    }
}