can't get the object name, when coerce object into xts

Question

I wrote functions which accept time series object, I want to coerce the input data into xts format, but when I do that, deparse(substitute()) become problematic, it should return the name of the object.

codes to reproduce the error:

library(xts)
data(sample_matrix)
matrixObj=sample_matrix

myFunc=function(data){
  print(deparse(substitute(data)))  
}

myFunc(matrixObj)

[1] "matrixObj" #This is what I want.

myFunc2=function(data){
  data=as.xts(data)#add this line to coerce data into xts format
  print(deparse(substitute(data)))  
}

myFunc2(matrixObj)

[1] "structure(c(50.0397819115463, 50.2304961977954, 50.420955209067, "
[2] "50.3734680543285, 50.2443255196795, 50.1321122972067, 50.0355467742705, "
[3] "49.9948860954217, 49.9122834457642, 49.8852887132391, 50.2125821224916, "
[4] "50.3238453485025, 50.4635862266585, 50.6172355897254, 50.620241173435, "
[5] "50.7414981135498, 50.4805101188755, 50.4138129108681, 50.3532310036568, "
[6] "50.1618813949374, 50.3600836896748, 50.0396626712588, 50.1095259574076, "
[7] "50.2073807897632, 50.1600826681477, 50.0604060861532, 49.9658575219043, " ...abbreviated...

Answer 1

It's because you're modifying the object in your function, not because of the type of the object. Passing an xts into myFunc provides the desired result

library(xts)
data(sample_matrix)
matrixObj=sample_matrix

xtsObj=as.xts(sample_matrix)

myFunc=function(data){

  print(deparse(substitute(data)))  
}

myFunc(xtsObj)
#[1] "matrixObj"

In addition, either using a different variable name for the xts object in your function or doing the coercion after getting the variable name would work:

library(xts)
data(sample_matrix)
matrixObj=sample_matrix

#use a different variable name for the xts object
myFunc3=function(data){
  xtsdata=as.xts(data)
  print(deparse(substitute(data)))  

}

myFunc3(matrixObj)
#[1] "matrixObj"

#get the name before doing the coercion
myFunc4=function(data){
  print(deparse(substitute(data)))  
  data=as.xts(data)

}

myFunc4(matrixObj)
#[1] "matrixObj"