I need to join two tables on the colum name. They come from different excel spreadsheets which I didn't create. I imported both sheets into R tables using the function read.xls from the gdata package.

Sometimes the names contains umlauts and other accents. They appear identical within the excel sheets but when I import them into R they are not the same. Hence my join doesn't join. I join using the sqldf function.

As an example : I see Lück in the two spreadsheets. In table1 of R this appears as L\374ck whereas in table2 it appears as L\303\274ck.

How can I best solve this problem? Is there a way to force an encoding when data is imported? Or should one try to force the comparison of strings in a different way?


Question: The Moon is slowly moving away from the earth. Does this mean that a total solar eclipse wasn't possible at some point in earth's history?
Answer: The moon is moving away from Earth. So in the past it was closer and its shadow was larger so a wider area experienced a total eclipse.

At some point in the future (in about 0.5 Billion years) a total solar eclipse will no longer be possible because the moon's shadow won't fall on the Earth.