[R] how to merge two files while preserving the number of rows of one file in merged one?

[Jeff Newmiller]

Read about the all.x and all.y arguments to ?merge.

On April 21, 2020 7:53:33 AM PDT, Ana Marija <sokovic.anamarija using gmail.com> wrote:
>Hello,
>
>> head(a)
>           ID_1 pheno
>1             0     B
>2 fam1000_G1000     0
>3 fam1001_G1001     0
>4 fam1003_G1003     1
>5 fam1005_G1005     0
>6 fam1009_G1009     0
>> head(b)
>           ID_1          ID_2 missing
>1             0             0       0
>2 fam1000_G1000 fam1000_G1000       0
>3 fam1001_G1001 fam1001_G1001       0
>4 fam1003_G1003 fam1003_G1003       0
>5 fam1005_G1005 fam1005_G1005       0
>6 fam1009_G1009 fam1009_G1009       0
>> dim(b)
>[1] 1602    3
>> dim(a)
>[1] 1652    2
>> m=merge(a,b,by="ID_1")
>> dim(m)
>[1] 1499    4
>> head(m)
>          ID_1 pheno         ID_2 missing
>1            0     B            0       0
>2 fam0110_G110     1 fam0110_G110       0
>3 fam0117_G117     1 fam0117_G117       0
>4 fam0124_G124  <NA> fam0124_G124       0
>
>I would like my merged file (m) to have the same number of lines like
>(b), that is 1602. Can you please let me know how would I do that?
>
>Thanks
>Ana
>
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-- 
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