[R] comparing two strings from data
Greg Snow
538280 at gmail.com
Thu Oct 12 23:16:06 CEST 2017
The error is because the read.csv function converted both columns to
factors. The simplest thing to do is to set stringsAsFactors=FALSE is
the call to read.csv so that they are compared as strings. You could
also call as.character on each of the columns if you don't want to
read the data in again.
Also, look at the match function, I think it will give you what you
want without the explicit looping.
On Thu, Oct 12, 2017 at 2:25 PM, Yasin Gocgun <yasing053 at gmail.com> wrote:
> Hi,
>
> I have two columns that contain numbers along with letters (as shown below)
> and have different lengths. Each entry in the first column is likely to be
> found in the second column at most once.
>
> For each entry of the first column, if that entry is found in the second
> column, I would like to get the corresponding index. For instance, if the
> first entry of the first column is 5th entry in the second column, I would
> like to keep this index 5.
>
> AST2017000005534 TUR2017000001428
> CTS2017000079930 CTS2017000071989
> CTS2017000079931 CTS2017000072015
>
> In a loop, when I use the following code to get those indices,
>
>
> data_2 = read.csv("excel_data.csv")
> column_1 = data_2$data1
> column_2 = data_2$data2
>
> match_list <- array(0,dim=c(310,1)); # 310 is the length of the first
> column
>
> for (indx in 1: 310){
> for(indx2 in 1:713){ # 713 is the length of the second column
> if(column_1[indx] == column_2[indx2] ){
> match_list[indx,1] = indx2;
> break;
> }
> }
> }
>
>
> R provides the following error:
>
> Error in Ops.factor(column_1[indx], column_2[indx2]) :
> level sets of factors are different
>
> So can someone explain me how I can resolve this issue?
>
> Thnak you,
>
> Yasin
>
> [[alternative HTML version deleted]]
>
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--
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com
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