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Yuan Chun Ding

2020-Apr-07 18:34 UTC

[R] to create a new variable based on values in other variables

Hi R users,


I want to create a new variable, Ravg, in data frame tem2 based on values of two
other variables m1 and m2.

the condition:

if m1 = 23 and m2 =23 then Ravg =23; 
else if m1 != 23 and m2=23 then Ravg =m1;
else if m1 =23 and m2 !=23 then Ravg=m2;
else Ravg=average of m1 and m2;

the Ravg variable should be  same as  m3 variable in the following small
example.

my R code did not generate errors but not generate a new variable.

Ravg <- "rare_allele"
  tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12, 23,
12.5, 5))
  for (r in 1:nrow(tem2)) { 
  if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {
    tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){
    tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r]
==23) {
    tem2[[Ravg]][r] ==tem2$m1[r]} else {
    tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}
                          }

Thank you,

Ding

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Thierry Onkelinx

2020-Apr-07 18:48 UTC

head link

[R] to create a new variable based on values in other variables

Dear Ding,

It seems that you are looking for the ifelse() function. Clear use of
pmax() and pmin() reduces the number of if statements.

m1 <- c(12, 23, 22, 23)
m2 <- c(23, 23, 3, 5)

Ravg <- ifelse(
  pmax(m1, m2) == 23,
  pmin(m1, m2),
  (m1 + m2) / 2
)

Best regards,

ir. Thierry Onkelinx
Statisticus / Statistician

Vlaamse Overheid / Government of Flanders
INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND
FOREST
Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance
thierry.onkelinx at inbo.be
Havenlaan 88 bus 73, 1000 Brussel
www.inbo.be

///////////////////////////////////////////////////////////////////////////////////////////
To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to say
what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey
///////////////////////////////////////////////////////////////////////////////////////////

<https://www.inbo.be>


Op di 7 apr. 2020 om 20:35 schreef Yuan Chun Ding <ycding at coh.org>:
> Hi R users,
>
>
> I want to create a new variable, Ravg, in data frame tem2 based on values
> of two other variables m1 and m2.
>
> the condition:
>
> if m1 = 23 and m2 =23 then Ravg =23;
> else if m1 != 23 and m2=23 then Ravg =m1;
> else if m1 =23 and m2 !=23 then Ravg=m2;
> else Ravg=average of m1 and m2;
>
> the Ravg variable should be  same as  m3 variable in the following small
> example.
>
> my R code did not generate errors but not generate a new variable.
>
> Ravg <- "rare_allele"
>   tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12,
> 23, 12.5, 5))
>   for (r in 1:nrow(tem2)) {
>   if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {
>     tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){
>     tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r]
> ==23) {
>     tem2[[Ravg]][r] ==tem2$m1[r]} else {
>     tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}
>                           }
>
> Thank you,
>
> Ding
>
> ----------------------------------------------------------------------
> ------------------------------------------------------------
> -SECURITY/CONFIDENTIALITY WARNING-
>
> This message and any attachments are intended solely for the individual or
> entity to which they are addressed. This communication may contain
> information that is privileged, confidential, or exempt from disclosure
> under applicable law (e.g., personal health information, research data,
> financial information). Because this e-mail has been sent without
> encryption, individuals other than the intended recipient may be able to
> view the information, forward it to others or tamper with the information
> without the knowledge or consent of the sender. If you are not the intended
> recipient, or the employee or person responsible for delivering the message
> to the intended recipient, any dissemination, distribution or copying of
> the communication is strictly prohibited. If you received the communication
> in error, please notify the sender immediately by replying to this message
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> due to the security risks, you do not wish to receive further
> communications via e-mail, please reply to this message and inform the
> sender that you do not wish to receive further e-mail from the sender.
> (LCP301)
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
	[[alternative HTML version deleted]]

Yuan Chun Ding

2020-Apr-07 19:05 UTC

head link

[R] to create a new variable based on values in other variables

Hi Thierry,

the values in the example data frame are fake numbers, my original data frame
has hundreds of row and values are in wide range, not min or max of two
variables, also the number 23 is also different in different data frames.

I agree I need to use vectorized ifelse, but I got confused when there are more
than two conditions inside of ifelse function. I will look into ifelse function

Thank you,

Ding



From: Thierry Onkelinx [thierry.onkelinx at inbo.be]

Sent: Tuesday, April 7, 2020 11:48 AM

To: Yuan Chun Ding

Cc: r-help mailing list

Subject: Re: [R] to create a new variable based on values in other variables


Dear Ding,

It seems that you are looking for the ifelse() function. Clear use of pmax() and
pmin() reduces the number of if statements.

m1 <- c(12, 23, 22, 23)
m2 <- c(23, 23, 3, 5)

Ravg <- ifelse(

  pmax(m1, m2) == 23,

  pmin(m1, m2),

  (m1 + m2) / 2

)

Best regards,

ir. Thierry Onkelinx
Statisticus / Statistician

Vlaamse Overheid / Government of Flanders

INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND
FOREST

Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance 

thierry.onkelinx at inbo.be

Havenlaan 88 bus 73, 1000 Brussel

www.inbo.be




///////////////////////////////////////////////////////////////////////////////////////////

To call in the statistician after the experiment is done may be no more than
asking him to perform a post-mortem examination: he may be able to say what the
experiment died of. ~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data. ~ Roger Brinner

The combination of some data and an aching desire for an answer does not ensure
that a reasonable answer can be extracted from a given body of data. ~ John
Tukey

///////////////////////////////////////////////////////////////////////////////////////////






























Op di 7 apr. 2020 om 20:35 schreef Yuan Chun Ding <ycding at coh.org>:



Hi R users,





I want to create a new variable, Ravg, in data frame tem2 based on values of two
other variables m1 and m2.



the condition:



if m1 = 23 and m2 =23 then Ravg =23; 

else if m1 != 23 and m2=23 then Ravg =m1;

else if m1 =23 and m2 !=23 then Ravg=m2;

else Ravg=average of m1 and m2;



the Ravg variable should be  same as  m3 variable in the following small
example.



my R code did not generate errors but not generate a new variable.



Ravg <- "rare_allele"

  tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12, 23,
12.5, 5))

  for (r in 1:nrow(tem2)) { 

  if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {

    tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){

    tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r]
==23) {

    tem2[[Ravg]][r] ==tem2$m1[r]} else {

    tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}

                          }



Thank you,



Ding



----------------------------------------------------------------------

------------------------------------------------------------

-SECURITY/CONFIDENTIALITY WARNING-  



This message and any attachments are intended solely for the individual or
entity to which they are addressed. This communication may contain information
that is privileged, confidential, or exempt from disclosure under applicable law
(e.g., personal health
 information, research data, financial information). Because this e-mail has
been sent without encryption, individuals other than the intended recipient may
be able to view the information, forward it to others or tamper with the
information without the knowledge
 or consent of the sender. If you are not the intended recipient, or the
employee or person responsible for delivering the message to the intended
recipient, any dissemination, distribution or copying of the communication is
strictly prohibited. If you received
 the communication in error, please notify the sender immediately by replying to
this message and deleting the message and any accompanying files from your
system. If, due to the security risks, you do not wish to receive further
communications via e-mail,
 please reply to this message and inform the sender that you do not wish to
receive further e-mail from the sender. (LCP301)



______________________________________________

R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see

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.

Bert Gunter

2020-Apr-07 19:53 UTC

head link

[R] to create a new variable based on values in other variables

You can use subscripting to generalize and avoid multiply nested
ifelse's which, I agree, can be a nightmare. However, you have to be
very careful about the logic of the conditions you create and the
order in which you apply them. It is very easy to wipe out an earlier
relationship with a later one (I speak from sad experience here). Note
that because the following uses subscripting, it's vectorized. But you
of course have to set up all your conditions manually. Note that your
last example condition is redundant, btw. As Thierry indicated,
depending on what you do, there can be shortcuts. To keep the solution
generalizable, I have not used any.
> tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12,
23, 12.5, 5))
> tem2$ravg <- rowMeans(tem2[,c("m1","m2")])## or use with() or within() for more complex functions that  you have
to code yourself.> cond1 <- with(tem2,m1!= 23 & m2 == 23)
> cond2  <- with(tem2, m1 == 23 & m2 != 23)
## etc.> tem2 <- within(tem2,{+       ravg[cond1] <- m1[cond1]
+       ravg[cond2] <- m2[cond2]
+    })>
> tem2  m1 m2   m3 ravg
1 12 23 12.0 12.0
2 23 23 23.0 23.0
3 22  3 12.5 12.5
4 23  5  5.0  5.0


Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Tue, Apr 7, 2020 at 11:34 AM Yuan Chun Ding <ycding at coh.org>
wrote:>
> Hi R users,
>
>
> I want to create a new variable, Ravg, in data frame tem2 based on values
of two other variables m1 and m2.
>
> the condition:
>
> if m1 = 23 and m2 =23 then Ravg =23;
> else if m1 != 23 and m2=23 then Ravg =m1;
> else if m1 =23 and m2 !=23 then Ravg=m2;
> else Ravg=average of m1 and m2;
>
> the Ravg variable should be  same as  m3 variable in the following small
example.
>
> my R code did not generate errors but not generate a new variable.
>
> Ravg <- "rare_allele"
>   tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12,
23, 12.5, 5))
>   for (r in 1:nrow(tem2)) {
>   if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {
>     tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){
>     tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r]
==23) {
>     tem2[[Ravg]][r] ==tem2$m1[r]} else {
>     tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}
>                           }
>
> Thank you,
>
> Ding
>
> ----------------------------------------------------------------------
> ------------------------------------------------------------
> -SECURITY/CONFIDENTIALITY WARNING-
>
> This message and any attachments are intended solely for the individual or
entity to which they are addressed. This communication may contain information
that is privileged, confidential, or exempt from disclosure under applicable law
(e.g., personal health information, research data, financial information).
Because this e-mail has been sent without encryption, individuals other than the
intended recipient may be able to view the information, forward it to others or
tamper with the information without the knowledge or consent of the sender. If
you are not the intended recipient, or the employee or person responsible for
delivering the message to the intended recipient, any dissemination,
distribution or copying of the communication is strictly prohibited. If you
received the communication in error, please notify the sender immediately by
replying to this message and deleting the message and any accompanying files
from your system. If, due to the security risks, you do not wish to receive
further communications via e-mail, please reply to this message and inform the
sender that you do not wish to receive further e-mail from the sender. (LCP301)
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

Yuan Chun Ding

2020-Apr-08 00:04 UTC

head link

[R] to create a new variable based on values in other variables

Hi Bert,

your code worked perfect.  you always make me learn new R code skills!

Thank you so much!!

Ding
________________________________________
From: Bert Gunter [bgunter.4567 at gmail.com]
Sent: Tuesday, April 7, 2020 12:53 PM
To: Yuan Chun Ding
Cc: r-help mailing list
Subject: Re: [R] to create a new variable based on values in other variables

You can use subscripting to generalize and avoid multiply nested
ifelse's which, I agree, can be a nightmare. However, you have to be
very careful about the logic of the conditions you create and the
order in which you apply them. It is very easy to wipe out an earlier
relationship with a later one (I speak from sad experience here). Note
that because the following uses subscripting, it's vectorized. But you
of course have to set up all your conditions manually. Note that your
last example condition is redundant, btw. As Thierry indicated,
depending on what you do, there can be shortcuts. To keep the solution
generalizable, I have not used any.
> tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12,
23, 12.5, 5))
> tem2$ravg <- rowMeans(tem2[,c("m1","m2")])## or use with() or within() for more complex functions that  you have
to code yourself.> cond1 <- with(tem2,m1!= 23 & m2 == 23)
> cond2  <- with(tem2, m1 == 23 & m2 != 23)
## etc.> tem2 <- within(tem2,{+       ravg[cond1] <- m1[cond1]
+       ravg[cond2] <- m2[cond2]
+    })>
> tem2  m1 m2   m3 ravg
1 12 23 12.0 12.0
2 23 23 23.0 23.0
3 22  3 12.5 12.5
4 23  5  5.0  5.0


Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Tue, Apr 7, 2020 at 11:34 AM Yuan Chun Ding <ycding at coh.org>
wrote:>
> Hi R users,
>
>
> I want to create a new variable, Ravg, in data frame tem2 based on values
of two other variables m1 and m2.
>
> the condition:
>
> if m1 = 23 and m2 =23 then Ravg =23;
> else if m1 != 23 and m2=23 then Ravg =m1;
> else if m1 =23 and m2 !=23 then Ravg=m2;
> else Ravg=average of m1 and m2;
>
> the Ravg variable should be  same as  m3 variable in the following small
example.
>
> my R code did not generate errors but not generate a new variable.
>
> Ravg <- "rare_allele"
>   tem2 <-data.frame(m1=c(12, 23, 22, 23), m2=c(23, 23, 3, 5), m3 =c(12,
23, 12.5, 5))
>   for (r in 1:nrow(tem2)) {
>   if (tem2$m1[r] ==23 & tem2$m2[r] ==23) {
>     tem2[[Ravg]][r] ==23} else if(tem2$m1[r] ==23 & tem2$m2[r] !=23){
>     tem2[[Ravg]][r] ==tem2$m2[r]} else if (tem2$m1[r] !=23 & tem2$m2[r]
==23) {
>     tem2[[Ravg]][r] ==tem2$m1[r]} else {
>     tem2[[Ravg]][r] == mean(tem2$m1[r] + tem2$m2[r])}
>                           }
>
> Thank you,
>
> Ding
>
> ----------------------------------------------------------------------
> ------------------------------------------------------------
> -SECURITY/CONFIDENTIALITY WARNING-
>
> This message and any attachments are intended solely for the individual or
entity to which they are addressed. This communication may contain information
that is privileged, confidential, or exempt from disclosure under applicable law
(e.g., personal health information, research data, financial information).
Because this e-mail has been sent without encryption, individuals other than the
intended recipient may be able to view the information, forward it to others or
tamper with the information without the knowledge or consent of the sender. If
you are not the intended recipient, or the employee or person responsible for
delivering the message to the intended recipient, any dissemination,
distribution or copying of the communication is strictly prohibited. If you
received the communication in error, please notify the sender immediately by
replying to this message and deleting the message and any accompanying files
from your system. If, due to the security risks, you do not wish to receive
further communications via e-mail, please reply to this message and inform the
sender that you do not wish to receive further e-mail from the sender. (LCP301)
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>
https://urldefense.com/v3/__https://stat.ethz.ch/mailman/listinfo/r-help__;!!Fou38LsQmgU!5Ho4zb8Yy0d9gaWdgkNkC1NGMpUUY6kjUlH-XhJmj9UzTaeukRr5IuBRIePx$
> PLEASE do read the posting guide
https://urldefense.com/v3/__http://www.R-project.org/posting-guide.html__;!!Fou38LsQmgU!5Ho4zb8Yy0d9gaWdgkNkC1NGMpUUY6kjUlH-XhJmj9UzTaeukRr5Io0-e-EB$
> and provide commented, minimal, self-contained, reproducible code.

R help - Apr 2020 - to create a new variable based on values in other variables

[R] to create a new variable based on values in other variables

[R] to create a new variable based on values in other variables

[R] to create a new variable based on values in other variables

[R] to create a new variable based on values in other variables

[R] to create a new variable based on values in other variables