Decision based on the headers of a data frame

Question

I have a list of data frames :

df
[[1]]
    ID SignalIntensity       SNR
1  109        6.182309 0.8453577
2  110       10.172777 4.3837078
3  111        7.292275 1.0725751
4  112        8.898467 2.3192185
5  113        9.591034 3.7133402
7  116        7.789323 1.3636656
8  117        7.194835 1.1349738
9  118        6.572773 0.9041846
11 120        9.371126 2.9968457
12 121        6.154944 0.7777584

[[2]]
    ID SignalIntensity       SNR
1  118        6.572773 0.9041846
2  119        5.377519 0.7098581
3  120        9.371126 2.9968457
4  121        6.154944 0.7777584
5  123        5.797446 0.7235425
6  124        5.573614 0.7019574
7  125        7.014537 0.3433343
8  126        6.089159 0.7971650
9  127        6.314820 0.7845944
10 131        5.342544 1.2300000

It has headers as ID SignalIntensity and SNR. I check the headers by names(df[[1]]). Now after checking the headers i need to take the decision such as if headers of df[[1]] are ID,SingnalIntensity and SNR then do something like

    If(names(df[[1]]=="ID"))
    {
    print("This is data from Illumina platform")

    my code..........
    } 
    else if{my code...........}

Here As You know it has three headers.

I know my way of doing is wrong like below trail

if(names(df[[1]]=="ID, SignalIntensity, SNR")), it give me
Error in if (names(df[[1]] == "ID, SignalIntensity, SNR")) { : argument is of length zero Which is quite obvious.

How to set if{} so that it matches all the three headers or(header of our choice either 1 r 2 r 3) and go to other code if true, otherwise do something else. Thanks

Something like: `if(length(intersect(names(df[[1]],c("ID","SignalIntensity","SNR")==3){ my code}` — zx8754, Mar 18 '15 at 11:41
@zx8754 is it `if(length(intersect(names(df[[1]],c("ID","SignalIntensity","SNR")==3){ my code}` or if(length(intersect(names(df[[1]],c("ID","SignalIntensity","SNR")==3)))){ my code} — Agaz Wani, Mar 18 '15 at 12:03
@zx8754 Error in as.vector(y) : argument "y" is missing, with no default — Agaz Wani, Mar 18 '15 at 13:06

score 1 · Answer 1 · answered Mar 18 '15 at 11:50

1

Try this code:

headers <- c("ID", "SNR") # can add more header names here
hasHeader <- is.element(headers, names(df[[1]])) # c(T, T)
sumHeader <- sum(hasHeader, na.rm=T)             # 2
result <- ifelse(sumHeader==length(sumHeader), T, F)

# result is T if "ID" and "SNR" are names of df[[1]]

answered Mar 18 '15 at 11:50

Tim Biegeleisen

502,043
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Thanks for your comments: Error in if (names(df[[1]] == "ID")) { : argument is of length zero – Agaz Wani Mar 18 '15 at 12:25
It seems like your `names(df[[1]])` is empty. Can you check to see whether this be the case? – Tim Biegeleisen Mar 18 '15 at 12:49
1

Its not empty. Your code should work. I think i am missing something here, as my code is very large. Thanks very much. – Agaz Wani Mar 18 '15 at 12:58

Colonel Beauvel · Answer 2 · 2015-03-18T12:10:20.323

1

If you want to proceed code directly:

wanted_colnames = c("ID","SignalIntensity","SNR")

lapply(df, function(u){
    if(any(wanted_colnames %in% names(u)))
    {
        # do something
    } else {
        # do something
    }
})

edited Mar 18 '15 at 12:10

answered Mar 18 '15 at 11:51

Colonel Beauvel

30,423
11
47
87

Thanks for your comments. Actually i don't want to filter out anything. I just want to take decision on the basis of my data frame headers. – Agaz Wani Mar 18 '15 at 12:11

score 1 · Accepted Answer · answered Mar 18 '15 at 14:30

Expanding on my comments, try this:

#dummy data
df <-
  list(
    data.frame(ID=1:5,
               SignalIntensity=runif(5),
               SNR=runif(5)),
    data.frame(ID=1:3,
               x=runif(3)),
    data.frame(ID=1:5,
               SignalIntensity=runif(5),
               SNR=runif(5)))

#check 1st data frame
if(length(intersect(names(df[[1]]),c("ID","SignalIntensity","SNR")))==3){
  print("Illumina platform")} else {
    print("Non Illumina platform")}
# [1] "Illumina platform"

#check all dataframes
lapply(df,function(i)
  if(length(intersect(names(i),c("ID","SignalIntensity","SNR")))==3){
    "Illumina platform"} else {
      "Non Illumina platform"})
# [[1]]
# [1] "Illumina platform"
# 
# [[2]]
# [1] "Non Illumina platform"
# 
# [[3]]
# [1] "Illumina platform"

Decision based on the headers of a data frame

3 Answers3