search
Search
Login
Unlock 100+ guides
menu
menu
search toc
close
Comments
Log in or sign up
Cancel
Post
account_circle
Profile
exit_to_app
Sign out
What does this mean?
Why is this true?
Give me some examples!
search
keyboard_voice
close
Searching Tips
Search for a recipe:
"Creating a table in MySQL"
Search for an API documentation: "@append"
Search for code: "!dataframe"
Apply a tag filter: "#python"
Useful Shortcuts
/ to open search panel
Esc to close search panel
to navigate between search results
d to clear all current filters
Enter to expand content preview
Doc Search
Code Search Beta
SORRY NOTHING FOUND!
mic
Start speaking...
Voice search is only supported in Safari and Chrome.
Shrink
Navigate to

NumPy | eye method

schedule Aug 12, 2023
Last updated
local_offer
PythonNumPy
Tags
tocTable of Contents
expand_more
mode_heat
Master the mathematics behind data science with 100+ top-tier guides
Start your free 7-days trial now!

Numpy's `eye(~)` method returns a 2D array with its diagonals filled with 1s, and all other entries filled with 0s.

Parameters

1. `N` | `int`

The size of the matrix (i.e. number of rows and columns).

2. `M`link | `int` | `optional`

The desired number of columns. By default, M=N.

3. `k`link | `int` | `optional`

The offset of the diagonals. If positive, then the diagonals will be shifted upwards, otherwise the diagonals will be shifted downwards. By default, `k=0`.

4. `dtype` | `string` or `type` | `optional`

The desired data type of the returned identity matrix. By default, dtype=Float.

Return value

A 2D Numpy array that represents an identity matrix.

Examples

Creating an identity matrix

To create an identity matrix of size 3:

``` np.eye(3) array([[1., 0., 0.], [0., 1., 0.], [0., 0., 1.]]) ```

To create an identity matrix of type `int64`:

``` np.eye(3, dtype="int64") array([[1, 0, 0], [0, 1, 0], [0, 0, 1]]) ```

Specifying the number of columns

To create an array with 4 columns, set `M=4` as so:

``` np.eye(3, M=4) array([[1., 0., 0., 0.], [0., 1., 0., 0.], [0., 0., 1., 0.]]) ```

Specifying an offset

To have the diagonals shifted upward by 1:

``` np.eye(3, k=1) array([[0., 1., 0.], [0., 0., 1.], [0., 0., 0.]]) ```

To have the diagonals shifted downward by 2:

``` np.eye(3, k=-2) array([[0., 0., 0.], [0., 0., 0.], [1., 0., 0.]]) ```
Published by Isshin Inada
Edited by 0 others
Did you find this page useful?
thumb_up
thumb_down
Comment
Citation
Ask a question or leave a feedback...
thumb_up
0
thumb_down
0
chat_bubble_outline
0
settings
Enjoy our search
Hit / to insta-search docs and recipes!
Navigation
Home Blog
Contact us