code not working for other shp files

Question

The question posed in here , has been solved but somehow it is not working for a different shp file. Any idea why? I have been trying with the shp file from Coloring the states

Answer 1

Your merge is matching each row more than once, creating duplicate rows in the data. Additionally there is an ordering problem, and you lose polygons when there isn't a matching row.

Replace

f_india <- merge(x=f_india, y=india@data, by.x="id", by.y="ID")

with

f_india <- merge(x=f_india, y=unique(india@data), by.x="id", by.y="ID",all.x=T)
f_india <- f_india[with(f_india, order(id, order)), ]

EDIT:

Here's the output I get. The grey polygons are caused by mismatched names, but this is the only issue I can see.