Transforming the data from wide format to long format

Question

I've the data which looks like the following:

Var1    Var1234 Var234  Var123456   Var12345678
  A        26     19        23          19
  B        25     10        11          27
  C        21     19        21          11
  D        29     18        22          26
  E        16     27        11          10

The reason for putting the weird looking variable name is to show that variable length are not same. I want to convert this data into following shape:

Var1    Var_names   Values
 A       Var1234      26
 B       Var1234      25
 C       Var1234      21
 D       Var1234      29
 E       Var1234      16
 A       Var234       19
 B       Var234       10
 C       Var234       19
 D       Var234       18
 E       Var234       27
 A      Var123456     23
 B      Var123456     11
 C      Var123456     21
 D      Var123456     22
 E      Var123456     11
 A      Var12345678   19
 B      Var12345678   27
 C      Var12345678   11
 D      Var12345678   26
 E      Var12345678   10

I was trying the following code:

new_data <- reshape2::melt(old_data, id = "Var1")

But it's giving the following error:

Using var1 as id variables
Error in match.names(clabs, names(xi)) : 
  names do not match previous names

Reshape function used:

new_data <- reshape(old_data, direction ="long", varying = list(names(old_data)[2:ncol(old_data)]), v.names="Value", idvar = "Var1")

Error:

Error in `row.names<-.data.frame`(`*tmp*`, value = paste(d[, idvar], times[1L],  : 
  invalid 'row.names' length

I followed this option, but it didn't help me.

Can anyone please tell me how to resolve the issue?

Thank you!

It is working for me based on the example showed. Which version of R and reshape2 you are using? My version is reshape2_1.4.1 and R 3.3.0 — akrun, Jun 08 '16 at 16:35
@Procrastinatus Maximus: I actually tried reshape as well. I'm getting this error. I used melt multiple times. But never came across this issue. — Beta, Jun 08 '16 at 17:07
Strange. I never had this issue with `reshape2` in any of the R versions I used (which is all of them since 2.15). — Jaap, Jun 08 '16 at 17:14
@akrun and ProcrastinatusMaximus: It seems to work with data.table melt. Thanks for your suggestions. — Beta, Jun 08 '16 at 17:15

Transforming the data from wide format to long format

0 Answers0