> ## Documentation Index
> Fetch the complete documentation index at: https://docs.domino.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Working with Datasets in MATLAB
If your Domino project uses a large number of files (for example, more than 10,000), or a single file larger than 8GB, consider using a [Domino dataset](/cloud/platform-capabilities/core-concepts/data/datasets/local-data).
The following summarizes the lifecycle of a dataset:
* Datasets are defined in a **.yaml** file, along with input folders and output folders.
* A newly defined dataset is stored in the input folder specified in the **.yaml** file. By default, the dataset in the input folder is read-only, while files in the output folder are writable.
* If you do not write anything to the output folder, the dataset remains unchanged.
* You must copy any files that you’d like to persist from the dataset in the input folder to the output folder.
* If you write to the output folder, the dataset files will be overwritten. However, datasets are saved as snapshots so you can roll back to a previous snapshot of the dataset if needed.
This topic describes how to use a dataset with the weather project.
## Step 1: Add a dataset to your Project
1. In the navigation pane, click **Data**.
2. Click **Create New Dataset**.
3. Type a **Name** (such as get-started-MATLAB-dataset) and description for your dataset, then click **Create Dataset**.
4. To take an initial snapshot to create the initial version of your dataset, in the navigation pane, click **Workspaces**. Click **Create New Workspace** and give it a name.
5. Select MATLAB as your workspace IDE. Click **Launch Now**. Your MATLAB workspace launches with a new folder used to store the data that is part of your dataset.
6. To locate the new folder, click the "/" in the file path of your MATLAB workspace. Next, go to the dataset folder that Domino created for you: `/domino/datasets/local/get-started-MATLAB-dataset`.
7. To populate the dataset, download weather station files from the same NOAA repository that you used earlier in the project. Use the back arrow to return to your work directory (**/mnt**), and create script named **downloadToDatasetDir.m**.
8. Copy and paste the following to create a function to download the NOAA data:
```matlab theme={null}
function downloadToDatasetDir()
% NOAA data URL
baseUrlString = "https://www.ncei.noaa.gov/data/global-historical-climatology-network-daily/access/";
% Prefix shared by weather stations in Argentina
baseWeatherStationId = 'AR0000000';
% the location to save the files – the dataset output directory
datasetFolder = "//domino/datasets/local/get-started-MATLAB-dataset/";
% There are 16 weather station files. We will iterate and download each one
for counter=1:16
if counter<10
weatherStationId = sprintf('%s%s%d', baseWeatherStationId, '0', counter);
else
weatherStationId = sprintf('%s%d', baseWeatherStationId, counter )
end
urlString = sprintf("%s%s%s", baseUrlString, weatherStationId, ".csv");
savedFileName = sprintf("%s%s%s", datasetFolder, weatherStationId, ".csv");
websave(savedFileName, urlString);
end
end
```
9. Save the file, then type **downloadToDatasetDir** to run it from the Command Window in your MATLAB workspace. Click the / in the navigation bar and go to **/domino/datasets/local/get-started-MATLAB-dataset** to see the output.
10. To save the files to Domino, in the navigation pane, click **Files Changes**. Click **Sync All Changes**.
11. In the navigation pane, click the Domino logo. Then, click **Data** and you can see that the dataset is listed.
12. Click the dataset to open a list of the files that you downloaded.
## Step 2: Create a snapshot
When you are ready to version the contents of a dataset, you can create a Snapshot.
1. From the navigation pane, click **Data**.
2. Double-click the dataset for which you want to create a snapshot.
3. Click **Take Snapshot > Include all files**.
4. In the Confirm Dataset Snapshot? window, type a tag such as "weather." You can use this tag to mount the snapshot with a friendly name in subsequent executions. Click **Confirm**.
When the snapshot is done, you can see it from the Snapshots list.
