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I have a data table and want to extract every fifth row from it to create a new table. Is there a command to achieve this?
Here is an sample of my data:
count Idf_Nr block 1 1233 B12 2 1233 B12 3 1446 B12 4 1446 B12 5 365 B12 6 365 B12 7 876 B12 8 876 B12 9 842 B12 10 842 B12 11 1092 B12 12 1092 B12 13 923 B12 14 923 B12 15 1266 B12 16 1266 B12 17 256 B12 18 256 B12 19 588 B12 20 588 B12 21 1074 B12 22 1074 B12 23 474 B12 24 474 B12 25 1421 B12 
936
To select every nth row of a DataFrame - we will use the slicing method. Slicing in pandas DataFrame is similar to slicing a list or a string in python. Suppose we want every 2nd row of DataFrame we will use slicing in which we will define 2 after two :: (colons).
To get the nth row in a Pandas DataFrame, we can use the iloc() method. For example, df. iloc[4] will return the 5th row because row numbers start from 0.
Use stripe(n, from = m) to get every nth row/column starting at row/column m. Use dplyr functions like starts_with , contains and matches to specify columns (but not rows).
For a data frame df, you can get df.new as:
df.new = df[seq(1, nrow(df), 5), ] This creates an index from row 1 to nrow (number of rows of the table) every 5 rows. You can play with the starting point and the 5 to extract other sequences.
105
One dplyr possibility for this task could be:
df %>% slice(which(row_number() %% 5 == 1)) count Idf_Nr block 1 1 1233 B12 2 6 365 B12 3 11 1092 B12 4 16 1266 B12 5 21 1074 B12 Or:
df %>% filter(row_number() %% 5 == 1) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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