A tree map is not used to see the tree structure. The tree is actually the information that is hidden. Especially if you use the treemap without borders/padding/bezels/names (IMO if you display those it ruins the usability of a treemap). What the tree map is good for is:
- seeing a flat representation of the entire space and therefore instantly seeing the largest files no matter how deeply nested. With a tree or a sunburst you need to drill down from largest folder to largest file because there are only so many concentric rings that can shown. With a flat file list ordered by size you lose all other information.
- seeing rough percentages by type. Maybe you have plenty of small videos taking space. Maybe you have just a few huge videos. Maybe you have one big video and plenty of small ones. All of this can be seen at a glance but is obscured by a summary by file type and is obscured by a sunburst or a tree because of depth.
- seeing the distribution of those file types. Are all of the small videos in the same place? Are they spread around and mixed with other files. Are certain types usually present together? For example if you store RAWs and Jpegs paired together you would be able to see that as a surface of two colors mixed together. If you store RAWs and Jpegs completely separated you would also be able to see that as two distinct surfaces of different colors..
- seeing similar structures. Since a tree map places surfaces near each other if they are neighbours or near neighbors in the tree structure, it is usually easy to spot duplicate trees because they look similar even when they are not identical. A duplicate finder is a separate tool and it also doesn't handle well the scenario of duplicate but changed and therefore not identical.
My problem with this is that it looks too similar to a CPU heat/component map.
And, frankly, the actual layout in treemaps is basically arbitrary. Indeed many early "disk utilization" charts that look a lot like treemaps were entirely based on physical location on the disk. As such, the logical layout was not on display, and you were only able to see the physical layout. Which was usually important, as you could see if there were obviously bad sectors or if fragmentation was out of hand.
That is, the very concept of "neighbor" that treemaps show is completely logical in nature, and doesn't really indicate any physical neighboring relationship at all. I suspect that is why I'm not a huge fan of them.
A tree map is not used to see the tree structure. The tree is actually the information that is hidden. Especially if you use the treemap without borders/padding/bezels/names (IMO if you display those it ruins the usability of a treemap). What the tree map is good for is:
- seeing a flat representation of the entire space and therefore instantly seeing the largest files no matter how deeply nested. With a tree or a sunburst you need to drill down from largest folder to largest file because there are only so many concentric rings that can shown. With a flat file list ordered by size you lose all other information.
- seeing rough percentages by type. Maybe you have plenty of small videos taking space. Maybe you have just a few huge videos. Maybe you have one big video and plenty of small ones. All of this can be seen at a glance but is obscured by a summary by file type and is obscured by a sunburst or a tree because of depth.
- seeing the distribution of those file types. Are all of the small videos in the same place? Are they spread around and mixed with other files. Are certain types usually present together? For example if you store RAWs and Jpegs paired together you would be able to see that as a surface of two colors mixed together. If you store RAWs and Jpegs completely separated you would also be able to see that as two distinct surfaces of different colors..
- seeing similar structures. Since a tree map places surfaces near each other if they are neighbours or near neighbors in the tree structure, it is usually easy to spot duplicate trees because they look similar even when they are not identical. A duplicate finder is a separate tool and it also doesn't handle well the scenario of duplicate but changed and therefore not identical.