## MATLAB Example Data Sets

MATLAB® has hundreds of data sets spanning a variety of file formats and sizes. These data sets are used in documentation examples and to demo software capabilities. This topic summarizes useful data sets in a variety of formats, but it is not a comprehensive list.

### Observational Data

`accidents.mat`

Data on US traffic accidents and fatalities in 2004 from the US Department of Transportation. The data covers all 50 states and the District of Columbia.

File Size: 8 KB

Data Size: 51 rows, 17 variables

```load accidents.mat ```

`census.mat`

US population data from 1790 – 1990.

File Size: 1 KB

Data Size: Two column vectors with 21 elements

```load census.mat ```

`airlinesmall.csv`

US domestic airline flight data from 1987 – 2008.

File Size: 11,747 KB

Data Size: 123,523 rows, 29 variables

See Analyze Big Data in MATLAB Using Tall Arrays for an example that loads and processes this data. Documentation must be installed to access this data.

`patients.mat`

Medical patient information for 100 fictional patients.

File Size: 3 KB

Data Size: 100 rows, 10 variables

`load patients.mat`

`outages.csv`

Data on electric utility outages in the US.

File Size: 99 KB

Data Size: 1,468 rows, 6 variables

Load the CSV data as a table:

`T = readtable('outages.csv');`

`penny.mat`

A detailed 3-D image of the surface of a US penny.

File Size: 2 KB

Data Size: 128-by-128 matrix

To view a surface plot of the penny, use the command:

`penny`
`edit penny.m`

`seamount.mat`

A seamount is an underwater mountain. The data set consists of a set of longitude (`x`) and latitude (`y`) locations, and corresponding seamount elevations (`z`) measured at those coordinates.

File Size: 2 KB

Data Size: Three column vectors with 294 elements.

```load seamount.mat ```

`wind.mat`

3-D data on air currents over North America. The data consists of `(x,y,z)` position components and `(u,v,w)` velocity components.

File Size: 142 KB

Data Size: Six matrices of size 35-by-41-by-15

```load wind.mat ```

### Image Data

`ngc6543a.jpg`

This NASA Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the "Cat's Eye Nebula." Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas and unusual shock-induced knots of gas.

File Size: 27 KB

Image Size: 600 x 650

```I = imread('ngc6543a.jpg'); imshow(I)```

`street1.jpg`

A picture of a city street including cars, pedestrians, signs, and buildings.

File Size: 37 KB

Image Size: 640 x 480

```I = imread('street1.jpg'); imshow(I)```

`street2.jpg`

A picture of a busy city intersection.

File Size: 39 KB

Image Size: 640 x 480

```I = imread('street2.jpg'); imshow(I)```

`mri.mat`

An MRI data set that contains 27 image slices of a human head. The images are arranged into a 4-D array of size 128-by-128-by-1-by-27.

File Size: 130 KB

Image Size: 302 x 221

```load mri.mat imshow(D(:,:,:,1),map)```

`durer.mat`

An image of Albrecht Dürer's Melancolia. Can you find the magic square matrix?

File Size: 273 KB

Image Size: 683 x 741

```load durer.mat imshow(X,map)```

`peppers.png`

A colorful picture of several varieties of peppers.

File Size: 281 KB

Image Size: 512 x 384

```I = imread('peppers.png'); imshow(I)```

`corn.tif`

A TIF file containing three images of corn (indexed, RGB, and grayscale).

File Size: 226 KB

Image Size: 312 x 415

View the indexed version of the image.

```[corn_indexed,map] = imread('corn.tif',1); imshow(corn_indexed,map)```
View the RGB version of the image.
```corn_rgb = imread('corn.tif',2); imshow(corn_rgb)```
View the grayscale version of the image.
```corn_gray = imread('corn.tif',3); imshow(corn_gray)```

`flujet.mat`

An image of a simulation of an astrophysical jet experiencing turbulence.

File Size: 21 KB

Image Size: 474 x 493

```load flujet.mat imshow(X,map)```

`spine.mat`

An X-ray image of a human spine.

File Size: 33 KB

Image Size: 664 x 460

```load spine.mat imshow(X,map)```

`mandrill.mat`

A colorful picture of a mandrill.

File Size: 184 KB

Image Size: 674 x 573

```load mandrill.mat imshow(X,map)```

### Geographic Data

`earth.mat`

A picture of earth.

File Size: 32 KB

Image Size: 424 x 350

```load earth.mat imshow(X,map)```

`cape.mat`

NOAA altitude data for New England, including Cape Cod.

File Size: 37 KB

Image Size: 534 x 453

```load cape.mat imshow(X,map)```

`landOcean.jpg`

An image of the earth. This image can be combined with `cloudCombined.jpg` to view a map of the earth with cloud cover.

File Size: 261 KB

Image Size: 2048 x 1024

View the earth image:

```E = imread('landOcean.jpg'); imshow(E)```

View the cloud cover image:

```C = imread('cloudCombined.jpg'); imshow(C)```
See Changing Transparency of Images, Patches or Surfaces for an example that overlays both images with transparency.

`cloudCombined.jpg`

An image of cloud coverage on the earth. This image can be combined with `landOcean.jpg` to view a map of the earth with cloud cover.

File Size: 810 KB

Image Size: 2048 x 1024

`tsunamis.xlsx`

Data on tsunami occurrences, including locations.

File Size: 25 KB

Data Size: 162 rows, 20 variables

```T = readtable('tsunamis.xlsx'); geobubble(T.Latitude,T.Longitude,T.MaxHeight) ```

`topo.mat`

Earth topography data, courtesy of the NOAA.

File Size: 115 KB

Data Size: Altitude data is a 180-by-360 matrix

`usapolygon.mat`

Latitude and longitude data for the perimeter of the contiguous United States.

File Size: 17 KB

Data Size: Two vectors with 4,205 elements

`load usapolygon.mat`

`usastates.mat`

Latitude and longitude data for each state in the contiguous United States. The data contains a structure array with three fields: `Lat`, `Lon`, and `Name`.

File Size: 45 KB

Data Size: Structure array of size 49-by-1

`load usastates.mat`

### Video and Audio Data

`shuttle.avi`

Video of a space shuttle launch without audio, courtesy of NASA.

File Size: 1,648 KB

Video Length: 4 s

To watch the video on your computer:

`winopen('shuttle.avi')`

`xylophone.mp4`

`xylophone.mpg`

Video of a xylophone being played. The MPG version has audio.

File Size: 465 KB (mp4) and 645 KB (mpg)

Video Length: 4 s

To watch the videos on your computer:

`winopen('xylophone.mp4')`
or
`winopen('xylophone.mpg')`

`handel.mat`

An excerpt of the Hallelujah chorus from Handel's Messiah.

File Size: 137 KB

Audio Length: 8.9 s

```load handel.mat sound(y,Fs)```
`chirp.mat`

Birds chirping.

File Size: 25 KB

Audio Length: 1.6 s

```load chirp.mat sound(y,Fs)```
`gong.mat`

A gong ringing.

File Size: 90 KB

Audio Length: 5.1 s

```load gong.mat sound(y,Fs)```
`laughter.mat`

Hearty laughter.

File Size: 121 KB

Audio Length: 6.4 s

```load laughter.mat sound(y,Fs)```
`mtlb.mat`

A person saying "MATLAB".

File Size: 32 KB

Audio Length: 0.5 s

```load mtlb.mat sound(mtlb,Fs)```
`splat.mat`

A comical splat sound.

File Size: 18 KB

Audio Length: 1.2 s

```load splat.mat sound(y,Fs)```
`train.mat`

A train whistle.

File Size: 30 KB

Audio Length: 1.6 s

```load train.mat sound(y,Fs)```