Type & Coercion Errors

Replacement length mismatch

Matches: replacement has (\d+) rows?, data has (\d+)

WHAT THIS ERROR MEANS

You tried to assign a value to a column or vector, but the length of the new value doesn't match the existing data.

1. Check the length of both sides of the assignment.

2. Use rep() or recycle properly.

3. Make sure your filter conditions are correct.

BAD — THIS CAUSES THE ERROR

df$new_col <- c(1, 2, 3)  # but df has 5 rows

GOOD — CORRECT APPROACH

df$new_col <- c(1, 2, 3, 4, 5)  # match row count

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