One of the things we noticed when mapping Noda Bi-Yehuda is that the map for Vol. I looks different from the map of Vol. II, and that his sphere of correspondence seems to shrink over time. Take a look at what I wrote in the post about this.
We now have another way to visualize this: distinct heatmaps for the two volumes. You really see how Vol II covers a far more compact area, especially relative to the overall number of responsa. Take a look:
We’ve got a new map of Rav Yosef Shaul Nathansohn’s Sho’el U-Meshiv. He wrote more responsa than there are pages of Talmud. If one learned Sho’el U-Meshiv Yomi it would take longer than Daf Yomi. That’s really something.
Anyhow, we mapped it. You can toggle both city maps and heat maps for Sho’el U-Meshiv and Maharsham. They were both Galician, one generation apart, so it really offers an interesting basis for comparison. I haven’t even started digging in.