Try an Example
Heatmaps are one of the best visualization tools for dense point data.
After selecting 'Heatmap' under 'Chart Type', you can check out an example before adding your own data. Clicking the 'try an example' button will show what a sample chart looks like after adding data and playing with the style. You'll also see what values and style attributes were selected for this specific heatmap, as well as the end result.
You can also use the data featured in this tutorial by clicking on 'Open This Data in Plotly' on the left-hand side. It'll open in your workspace.
Add Your Data to Plotly
Head to Plotly’s new online workspace and add your data. You have the option of typing directly in the grid, uploading your file, or entering a URL of an online dataset. Plotly accepts .xls, .xlsx, or .csv files. For more information on how to enter your data, see this tutorial.
Create a Chart
After adding your own data, go to GRAPH on the left-hand side, then 'Create'. Choose 'Heatmap' under 'Chart type’.
Click on GRAPH on the left-hand side to add your axes to your heatmap. After selecting ‘Heatmap', you should then fill out the Z, X and Y dropdown to create the plot.
This will create a raw heatmap, as seen below.
Style a Chart
You can choose your colorscale, text position, or typeface. Click on STYLE on the left-hand side to play around with the style of your chart.
To change the color gradients of your heatmap, select ‘Traces’ under the same STYLE tab, and choose the colorscale you want.
After you've chosen your colorscale, you have the option to smooth your heatmap to create a continuous heatmap. So far, we've had it with the 'Smoothing' option off.
This is when the 'Smoothing' option is selected.
To add a title to your plot, you can type it directly on the title by double-clicking it. The same can be done for the axis labels and legend.
Another option is to visit the 'Layout' section under STYLE, click on 'Text' and enter your title in the box, as shown below. Note that certain typeface are only available with a PRO subscription. Click here to upgrade!
Save and Share
Your heatmap is now done! Click SAVE on the left-hand side.
Give your PLOT and DATA a filename and select them as 'Public' or 'Private'. For more information on how sharing works, including the difference between private, public, and secret sharing, visit this page.