Hello,
I want to do fisher test for the rows in data file which has value less than
5 otherwise chi square test .The p values from both test should be stored in
one resulted file. but there is some problem with bold if statement. I don't
know how
implement this line properly.
x = cbind(obs1,obs2,exp1,exp2)
a = matrix(c(0,0,0,0), ncol=2, byrow =TRUE) #matrix with initialized
values
for (i in 1: length(x[,1]))
{
*if((x[i,1] || x[i,2] || x[i,3] || x[i,4]) < 5)*
{
a[1,1] <- x[i,1];
a[1,2] <- x[i,2];
a[2,1] <- x[i,3];
a[2,2] <- x[i,4];
result <- fisher.test(a)
write.table(result[["p.value"]],file="results.txt",
sep="\n", append=TRUE, col.names=FALSE, row.names=FALSE);
}
else
{
a[1,1] <- x[i,1];
a[1,2] <- x[i,2];
a[2,1] <- x[i,3];
a[2,2] <- x[i,4];
result <- chisq.test(a)
write.table(result[["p.value"]],file="results.txt",
sep="\n", append=TRUE, col.names=FALSE, row.names=FALSE);}
}
Regards
R
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reena wrote> > Hello, > > I want to do fisher test for the rows in data file which has value less > than 5 otherwise chi square test .The p values from both test should be > stored in one resulted file. but there is some problem with bold if > statement. I don't know how > implement this line properly. > > > x = cbind(obs1,obs2,exp1,exp2) > a = matrix(c(0,0,0,0), ncol=2, byrow =TRUE) #matrix with > initialized values > > for (i in 1: length(x[,1])) > { > *if((x[i,1] || x[i,2] || x[i,3] || x[i,4]) < 5)* > >Hello, Try *if(any(x[i,] <5))* Merry Christmas Rui Barradas -- View this message in context: http://r.789695.n4.nabble.com/if-statement-problem-tp4230026p4230135.html Sent from the R help mailing list archive at Nabble.com.
This is almost Circle 8.1.7 of 'The R Inferno': http://www.burns-stat.com/pages/Tutor/R_inferno.pdf but is making the mistake in the other direction. On 23/12/2011 22:40, reena wrote:> Hello, > > I want to do fisher test for the rows in data file which has value less than > 5 otherwise chi square test .The p values from both test should be stored in > one resulted file. but there is some problem with bold if statement. I don't > know how > implement this line properly. > > > x = cbind(obs1,obs2,exp1,exp2) > a = matrix(c(0,0,0,0), ncol=2, byrow =TRUE) #matrix with initialized > values > > for (i in 1: length(x[,1])) > { > *if((x[i,1] || x[i,2] || x[i,3] || x[i,4])< 5)* > { > a[1,1]<- x[i,1]; > a[1,2]<- x[i,2]; > a[2,1]<- x[i,3]; > a[2,2]<- x[i,4]; > result<- fisher.test(a) > write.table(result[["p.value"]],file="results.txt", > sep="\n", append=TRUE, col.names=FALSE, row.names=FALSE); > } > > else > { > a[1,1]<- x[i,1]; > a[1,2]<- x[i,2]; > a[2,1]<- x[i,3]; > a[2,2]<- x[i,4]; > result<- chisq.test(a) > write.table(result[["p.value"]],file="results.txt", > sep="\n", append=TRUE, col.names=FALSE, row.names=FALSE);} > } > > Regards > R > > -- > View this message in context: http://r.789695.n4.nabble.com/if-statement-problem-tp4230026p4230026.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >-- Patrick Burns pburns at pburns.seanet.com twitter: @portfolioprobe http://www.portfolioprobe.com/blog http://www.burns-stat.com (home of 'Some hints for the R beginner' and 'The R Inferno')
Hello again.
I don't understand what didn't work.
First, it seems better to use 'nrow', the result is the same
stopifnot(length(x[,1]) == nrow(x))
Then your multiple OR condition.
#if((x[i,1] || x[i,2] || x[i,3] || x[i,4]) < 5)
x <- matrix(1:24, ncol=4)
for(i in 1:nrow(x))
if(any(x[i,] < 5))
cat("At least one is TRUE:", i, "\n")
for(i in 1:nrow(x))
if((x[i,1] < 5) | (x[i,2] < 5) | (x[i,3] < 5) | (x[i,4] < 5))
cat("The same with '|':", i, "\n")
In the second example each condition IS a condition. Unlike your original
"compound" one.
The 'Introduction to R' clearly states '|' as the union of the
logical
expressions, The section is 2.4.
Also read Patrick's PDF, the parts I've read are great and very usefull.
(Thanks, Patrick, I was unaware of R inferno.pdf)
As a side note, you are duplicating the matrix 'a' assignement. Why not
just
before the 'if'?
Then, you could simply test if any 'a' is less than 5.
for (i in 1: row(x))
{
a[1,1] <- x[i,1];
a[1,2] <- x[i,2];
a[2,1] <- x[i,3];
a[2,2] <- x[i,4];
if(any(a < 5))
{
etc...
(Or use the compound '|' ).
Rui Barradas
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