A fancy ndarray is anndarray which supports slicing via indexing expressions.

varndarray2array=require('@stdlib/ndarray-to-array');varndarray=require('@stdlib/ndarray-ctor');// Create a plain ndarray:varbuffer=[1,2,3,4,5,6];varx=newndarray('generic',buffer,[6],[1],0,'row-major');// returns <ndarray>// Convert to a fancy ndarray:vary=ndarray2fancy(x);// Select the first 3 elements:varz=y[':3'];// returns <ndarray>vararr=ndarray2array(z);// returns [ 1, 2, 3 ]// Select every other element, starting with the second element:z=y['1::2'];// returns <ndarray>arr=ndarray2array(z);// returns [ 2, 4, 6 ]// Reverse the array, starting with last element and skipping every other element:z=y['::-2'];// returns <ndarray>arr=ndarray2array(z);// returns [ 6, 4, 2 ]

npm install @stdlib/ndarray-to-fancy

Alternatively,

• To load the package in a website via ascript tag without installation and bundlers, use theES Module available on theesm branch (seeREADME).
• If you are using Deno, visit thedeno branch (seeREADME for usage intructions).
• For use in Observable, or in browser/node environments, use theUniversal Module Definition (UMD) build available on theumd branch (seeREADME).

Thebranches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

varndarray2fancy=require('@stdlib/ndarray-to-fancy');

Converts anndarray to an object supporting fancy indexing.

console.log('TODO');

The function supports the following options:

• cache: cache for resolving ndarray index objects. Must have aget method which accepts a single argument: a string identifier associated with an ndarray index.

  If an ndarray index associated with a provided identifier exists, theget method should return an object having the following properties:

  • data: the underlying index ndarray.
  • type: the index type. Must be either'mask','bool', or'int'.
  • kind: the index kind. Must be either'','cartesian', or'linear'.
  • dtype: thedata type of the underlying ndarray.

  If an ndarray index is not associated with a provided identifier, theget method should returnnull.

  Default:ndindex.

• strict: boolean indicating whether to enforce strict bounds checking. Default:false.

By default, the function returns a fancy ndarray which doesnot enforce strict bounds checking. For example,

console.log('TODO');

To enforce strict bounds checking, set thestrict option totrue.

console.log('TODO');

Returns a function for converting anndarray to an object supporting fancy indexing.

varfcn=ndarray2fancy.factory();console.log('TODO');

The function supports the following options:

• cache: default cache for resolving ndarray index objects. Must have aget method which accepts a single argument: a string identifier associated with an ndarray index.

  If an ndarray index associated with a provided identifier exists, theget method should return an object having the following properties:

  • data: the underlying index ndarray.
  • type: the index type. Must be either'mask','bool', or'int'.
  • kind: the index kind. Must be either'','cartesian', or'linear'.
  • dtype: thedata type of the underlying ndarray.

  If an ndarray index is not associated with a provided identifier, theget method should returnnull.

  Default:ndindex.

• strict: boolean indicating whether to enforce strict bounds checking by default. Default:false.

By default, the function returns a function which, by default, doesnot enforce strict bounds checking. For example,

varfcn=ndarray2fancy.factory();console.log('TODO');

To enforce strict bounds checking by default, set thestrict option totrue.

varfcn=ndarray2fancy.factory({'strict':true});console.log('TODO');

The returned function supports the same options as above. When the returned function is provided option values, those values override the factory method defaults.

Wraps a provided ndarray as an ndarray index object.

console.log('TODO');

For documentation and usage, seendindex.

• A fancy ndarray shares thesame data as the provided inputndarray. Hence, any mutations to the returned ndarray will affect the underlying input ndarray and vice versa.
• For operations returning a new ndarray (e.g., when slicing or invoking an instance method), a fancy ndarray returns a new fancy ndarray having the same configuration as specified byoptions.
• A fancy ndarray supports indexing using positive and negative integers (both numeric literals and strings),Slice andMultiSlice instances,subsequence expressions, andindex arrays (boolean, mask, and integer).
• A fancy ndarray supports all properties and methods of the input ndarray, and, thus, a fancy ndarray can be consumed by any API which supports ndarray-like objects.
• Indexing expressions provide a convenient and powerful means for creating and operating on ndarray views; however, their use does entail a performance cost. Indexing expressions are best suited for interactive use (e.g., in theREPL) and scripting. For performance critical applications, prefer equivalent functional APIs supporting ndarray-like objects.
• In older JavaScript environments which donot supportProxy objects, the use of indexing expressions isnot supported.

// TODO: see array/to-fancy

// TODO: only applies to non-zero-dimensional ndarrays. In non-strict mode, out-of-bounds indices returnundefined and fail to assign.

// TODO: see array/to-fancy

// TODO: see array/to-fancy

• @stdlib/array-to-fancy:convert an array to an object supporting fancy indexing.
• @stdlib/ndarray-array:multidimensional arrays.
• @stdlib/ndarray-ctor:multidimensional array constructor.
• @stdlib/ndarray-fancy:fancy multidimensional array constructor.

This package is part ofstdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to developstdlib, see the main projectrepository.

SeeLICENSE.

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