Struct ndarray_npz::NpzWriter
source · pub struct NpzWriter<W: Write + Seek> { /* private fields */ }
Expand description
Writer for .npz
files.
Note that the inner ZipWriter
is wrapped in a BufWriter
when
writing each array with .add_array()
. If desired,
you could additionally buffer the innermost writer (e.g. the
File
when writing to a file) by wrapping it in a
BufWriter
. This may be somewhat beneficial if the arrays are large and
have non-standard layouts but may decrease performance if the arrays have
standard or Fortran layout, so it’s not recommended without testing to
compare.
Example
use ndarray_npz::{
ndarray::{array, aview0, Array1, Array2},
NpzWriter,
};
use std::fs::File;
let mut npz = NpzWriter::new(File::create("arrays.npz")?);
let a: Array2<i32> = array![[1, 2, 3], [4, 5, 6]];
let b: Array1<i32> = array![7, 8, 9];
npz.add_array("a", &a)?;
npz.add_array("b", &b)?;
npz.add_array("c", &aview0(&10))?;
npz.finish()?;
Implementations§
source§impl<W: Write + Seek> NpzWriter<W>
impl<W: Write + Seek> NpzWriter<W>
sourcepub fn new(writer: W) -> NpzWriter<W>
pub fn new(writer: W) -> NpzWriter<W>
Creates a new .npz
file without compression. See numpy.savez
.
Ensures .npy
files are 64-byte aligned for memory-mapping via NpzView
/NpzViewMut
.
sourcepub fn new_compressed(writer: W) -> NpzWriter<W>
Available on crate feature compressed
only.
pub fn new_compressed(writer: W) -> NpzWriter<W>
compressed
only.Creates a new .npz
file with compression. See numpy.savez_compressed
.
sourcepub fn add_array<N, S, D>(
&mut self,
name: N,
array: &ArrayBase<S, D>
) -> Result<(), WriteNpzError>where
N: Into<String>,
S::Elem: WritableElement,
S: Data,
D: Dimension,
pub fn add_array<N, S, D>( &mut self, name: N, array: &ArrayBase<S, D> ) -> Result<(), WriteNpzError>where N: Into<String>, S::Elem: WritableElement, S: Data, D: Dimension,
Adds an array with the specified name
to the .npz
file.
To write a scalar value, create a zero-dimensional array using arr0
or
aview0
.
Errors
Adding an array can fail with WriteNpyError
.
sourcepub fn finish(self) -> Result<W, WriteNpzError>
pub fn finish(self) -> Result<W, WriteNpzError>
Calls .finish()
on the zip file and
.flush()
on the writer, and then returns the writer.
This finishes writing the remaining zip structures and flushes the
writer. While dropping will automatically attempt to finish the zip
file and (for writers that flush on drop, such as
BufWriter
) flush the writer, any errors that
occur during drop will be silently ignored. So, it’s necessary to call
.finish()
to properly handle errors.
Errors
Finishing the zip archive can fail with ZipError
.