[R] operation with if/else on a dataframe
Hi to all,
I have this dataframe (I show the first six rows)
head(table)
A RFold.Change P.Value
Count1 Count2
1 ENSRNOE002_at 0 1.13 0.601
1
2 ENSRNOE009_at 0-1.04 0.733
3
3 ENSRNOE020_at 0-1.08 0.680
0
4 ENSRNOE021_at 0-1.31 0.201
2
5 ENSRNOE023_at 0-1.06 0.643
3
6 ENSRNOE024_at 0-1.14 0.403
3
I would like to generate a function that determine for each row a new value
(resulting in a new vector of values to add to the dataframe).
The function should give for every row the same value showed in column R.
However,I need of this because not all the R-values reported in this table
are correctly determined following the criteria mentioned below.
These new values calculated by the function must be:
1)UP
if all the following conditions are verified in a certain row:
Fold.Change is = +1.5,
P.Value is 0.05
Count1 = 2
2)DOWN
if all the following conditions are verified in a certain row:
Fold.Change is = -1.5,
P.Value is 0.05
Count2 = 2
3) 0 if both of previous conditions are not verified
So I have set these fllowing parameters (new objects) because I'll have to
repeat this procedure to different dataframes in which the order of columns
of interest might change (So I can change these parameters depending on the
order of the columns in any different table)
Fold.change - 3 #(because in this table, Fold.Change value is the third
column and so on...)
P.Value - 4
Count1 - 5
Count2 - 6
The function is:
func_UP_0_DOWN - function(x) {
if (x[Fold.Change] = 1.5 x[P.Value] = 0.05 x[Count1] = 2) {
return (UP)} else {
if (x[Fold.Change] = -1.5 x[P.Value] = 0.05 x[Count2] = 2) {
return (DOWN)} else {
return(0)}
} }
and then I have decided to apply the function for every row:
values.vector - apply(table,1,func_UP_0_DOWN)
But when I check the resulting vector of calculated values:
table(values.vector)
values.vector
0
192279
I have all zero but this is wrong since I expect some UP and DOWN
However, if I apply this function on a single row in which I just know that
there is a UP-value...
(for example row 66):
table[66,]
RFold.Change
P.Value Count1 Count2
66 ENSRNOE162_atUP 1.84 0.013
3
the function seems to work correctly:
func_UP_0_DOWN(table[66,])
[1] UP
This is my problem, I cannot use the function to recalculate values in
R-column for all rows in my dataframe. I don't understand where is the
problem, can someone help me?
Thanks a lot!!
Francesco
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Re: [R] operation with if/else on a dataframe
On Thu, 2009-10-29 at 01:47 -0700, Fran100681 wrote: Hi to all, I have this dataframe (I show the first six rows) head(table) A RFold.Change P.Value Count1 Count2 1 ENSRNOE002_at 0 1.13 0.601 1 2 ENSRNOE009_at 0-1.04 0.733 3 3 ENSRNOE020_at 0-1.08 0.680 0 4 ENSRNOE021_at 0-1.31 0.201 2 5 ENSRNOE023_at 0-1.06 0.643 3 6 ENSRNOE024_at 0-1.14 0.403 3 I would like to generate a function that determine for each row a new value (resulting in a new vector of values to add to the dataframe). The function should give for every row the same value showed in column R. However,I need of this because not all the R-values reported in this table are correctly determined following the criteria mentioned below. These new values calculated by the function must be: 1)UP if all the following conditions are verified in a certain row: Fold.Change is = +1.5, P.Value is 0.05 Count1 = 2 2)DOWN if all the following conditions are verified in a certain row: Fold.Change is = -1.5, P.Value is 0.05 Count2 = 2 3) 0 if both of previous conditions are not verified So I have set these fllowing parameters (new objects) because I'll have to repeat this procedure to different dataframes in which the order of columns of interest might change (So I can change these parameters depending on the order of the columns in any different table) Fold.change - 3 #(because in this table, Fold.Change value is the third column and so on...) P.Value - 4 Count1 - 5 Count2 - 6 [ Quote text] This is my problem, I cannot use the function to recalculate values in R-column for all rows in my dataframe. I don't understand where is the problem, can someone help me? Thanks a lot!! Francesco Francesco, I think you solve this problem with a simple way. Remember in R the most function and operations are vectorized so look this example: set.seed(123) x-rpois(20,5) y-rpois(20,15) z-rpois(20,10) dta-data.frame(x,y,z) dta dta$NEW-ifelse(x5 y15 z10,UP, ifelse(x5 y15 z10,DOWN, 0)) dta First, I use ifelse command to simplify your nested conditional situation. Second, I know that R test this nested condition in order so the first position will result test x[1],y[1] and z[1], the second postion will result test x[2],y[2] and z[2] ... The new vector result is the same order the original data.frame so I use dta$NEW to create a new column in data.frame -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] operation with if/else on a dataframe
Ok, thank you a lot!! Bernardo Rangel tura wrote: On Thu, 2009-10-29 at 01:47 -0700, Fran100681 wrote: Hi to all, I have this dataframe (I show the first six rows) head(table) A RFold.Change P.Value Count1 Count2 1 ENSRNOE002_at 0 1.13 0.601 1 2 ENSRNOE009_at 0-1.04 0.733 3 3 ENSRNOE020_at 0-1.08 0.680 0 4 ENSRNOE021_at 0-1.31 0.201 2 5 ENSRNOE023_at 0-1.06 0.643 3 6 ENSRNOE024_at 0-1.14 0.403 3 I would like to generate a function that determine for each row a new value (resulting in a new vector of values to add to the dataframe). The function should give for every row the same value showed in column R. However,I need of this because not all the R-values reported in this table are correctly determined following the criteria mentioned below. These new values calculated by the function must be: 1)UP if all the following conditions are verified in a certain row: Fold.Change is = +1.5, P.Value is 0.05 Count1 = 2 2)DOWN if all the following conditions are verified in a certain row: Fold.Change is = -1.5, P.Value is 0.05 Count2 = 2 3) 0 if both of previous conditions are not verified So I have set these fllowing parameters (new objects) because I'll have to repeat this procedure to different dataframes in which the order of columns of interest might change (So I can change these parameters depending on the order of the columns in any different table) Fold.change - 3 #(because in this table, Fold.Change value is the third column and so on...) P.Value - 4 Count1 - 5 Count2 - 6 [ Quote text] This is my problem, I cannot use the function to recalculate values in R-column for all rows in my dataframe. I don't understand where is the problem, can someone help me? Thanks a lot!! Francesco Francesco, I think you solve this problem with a simple way. Remember in R the most function and operations are vectorized so look this example: set.seed(123) x-rpois(20,5) y-rpois(20,15) z-rpois(20,10) dta-data.frame(x,y,z) dta dta$NEW-ifelse(x5 y15 z10,UP, ifelse(x5 y15 z10,DOWN, 0)) dta First, I use ifelse command to simplify your nested conditional situation. Second, I know that R test this nested condition in order so the first position will result test x[1],y[1] and z[1], the second postion will result test x[2],y[2] and z[2] ... The new vector result is the same order the original data.frame so I use dta$NEW to create a new column in data.frame -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- View this message in context: http://www.nabble.com/operation-with-if-else-on-a-dataframe-tp26109081p26110139.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
