[R] How to sum some columns based on their names

[Charles Determan Jr]

You can use grep with some basic regex, index your dataframe, and colSums

colSums(df[,grep("*6574*|*7584*|*85*", colnames(df))])
colSums(df[,grep("f6574*|f7584*|f85*", colnames(df))])


Regards,
Dr. Charles Determan

On Mon, Oct 13, 2014 at 7:57 AM, Kuma Raj <pollaroid at gmail.com> wrote:

> I want to sum columns based on their names. As an exampel how could I
> sum columns which contain 6574, 7584 and 85 as column names?  In
> addition, how could I sum those which contain 6574, 7584 and 85 in
> ther names and have a prefix "f". My data contains several variables
> with
>
> I want to sum columns based on their names. As an exampel how could I
> sum columns which contain 6574, 7584 and 85 as column names?  In
> addition, how could I sum those which contain 6574, 7584 and 85 in
> ther names and have a prefix "f". My data contains several variables
> with
>
> dput(df1)
> structure(list(date = structure(c(1230768000, 1230854400, 1230940800,
> 1231027200, 1231113600, 1231200000, 1231286400, 1231372800, 1231459200,
> 1231545600, 1231632000), class = c("POSIXct", "POSIXt"), tzone = "UTC"),
>     f014card = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), f1534card = c(0,
>     1, 1, 0, 0, 1, 0, 0, 1, 0, 1), f3564card = c(1, 6, 1, 5,
>     5, 4, 4, 7, 6, 4, 6), f6574card = c(3, 6, 4, 5, 5, 2, 10,
>     3, 4, 2, 4), f7584card = c(13, 6, 1, 4, 10, 6, 8, 12, 10,
>     4, 3), f85card = c(5, 3, 1, 0, 2, 10, 7, 9, 1, 7, 3), m014card = c(0,
>     0, 0, 0, 0, 0, 0, 0, 0, 0, 0), m1534card = c(0, 0, 1, 0,
>     0, 0, 0, 1, 1, 1, 0), m3564card = c(12, 7, 4, 7, 12, 13,
>     12, 7, 12, 2, 11), m6574card = c(3, 4, 8, 8, 8, 10, 7, 6,
>     7, 7, 5), m7584card = c(8, 10, 5, 4, 12, 7, 14, 11, 9, 1,
>     11), m85card = c(1, 4, 3, 0, 3, 4, 5, 5, 4, 5, 0)), .Names = c("date",
> "f014card", "f1534card", "f3564card", "f6574card", "f7584card",
> "f85card", "m014card", "m1534card", "m3564card", "m6574card",
> "m7584card", "m85card"), class = "data.frame", row.names = c("1",
> "2", "3", "4", "5", "6", "7", "8", "9", "10", "11"))
>
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>



-- 
Dr. Charles Determan, PhD
Integrated Biosciences

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