# Eroding Commitment

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There’s an old saying that goes: “If you dream and want something hard enough, but have no commitment….then you’re probably full of shit”. After having finished the Getting and Cleaning Data course on Coursera, I haven’t typed a single line of R code in a long time; and since i was only just starting out on the basics, my foundations in the language are a little shaky again. So i had to start all over again.

Below is a function that loops through an entire dataframe and find all the column names that contain a given value.

searchCol = function(name, dataframe){ x = 0 newList = c() #This will be vector that would be returned #Start loop for all the values to be seached for for(i in 1:length(name)){ #Start loop for each row in the dataframe... for(j in 1:nrow(dataframe)){ #...same thing for the columns for(k in 1:ncol(dataframe)){ #If the matching criteria is met, add the value to the newList vector if(dataframe[j,k] == name[i]){ newList[x+1] = names(dataframe)[k] x = x+1 } } } } return(newList) }

Below is a simple demostration:

mat = data.frame(matrix(1:50, 5, 10)) mat

`X1 X2 X3 X4 X5 X6 X7 X8 X9 X10`

1 1 6 11 16 21 26 31 36 41 46

2 2 7 12 17 22 27 32 37 42 47

3 3 8 13 18 23 28 33 38 43 48

4 4 9 14 19 24 29 34 39 44 49

5 5 10 15 20 25 30 35 40 45 50

So to find which columns do the figures 28 and 39 fall in..

tst = c(28, 39) searchCol(tst, mat)

…we would get:

`[1] "X6" "X8"`

God, i hate having to start from scratch again.

Tagged: functions, programming, r

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