Help "deleting negative values in a matrix, and do statistic analysis"

Hello,

Try
(x is your matrix)

rowMeans(x)
apply(x, 1, function(y) mean( y[y >= 0] ))

Hope this helps,

Rui Barradas

york8866 wrote
Dear all,

I have encountered a problem with such a dataset:

1	52	2	5	2	6
15	23	2	1	3	3
2	5	1	9	8	9
6	-5	3	6	-5	96
-1	6	3	8	5	9
.	.	.	.	.	.
.	.	.	.	.	.

I want to calculate the means of each row of the dataset. In addition, I
need to delete the negative values in each row first before the
calculation of the means.

can anyone show me how to deal with it?

thanks,

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Hi,  Rui,

I tried your code. It did not work. 

thanks,

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It looks fine to me. Why do you say it does not work?

Any error messages?

John Kane
Kingston ON Canada
-----Original Message-----
From: yu_york at hotmail.com
Sent: Tue, 8 May 2012 10:06:07 -0700 (PDT)
To: r-help at r-project.org
Subject: Re: [R] Help "deleting negative values in a matrix, and do
statistic analysis"

Hi,  Rui,

I tried your code. It did not work.

thanks,

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Hi, John,

the code ran well.

however, somehow, the means were not calculated correctly using the
following code.

test <- read.csv("Rtestdataset.csv", as.is=T,header=T)  
test <- data.frame(test)
test
rowMeans(test)
apply(test,1,function(y)mean(y>=0))

Is there anything wrong?
thanks,

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Hello,

york8866 wrote
Hi, John,

the code ran well.

however, somehow, the means were not calculated correctly using the
following code.

test <- read.csv("Rtestdataset.csv", as.is=T,header=T)  
test <- data.frame(test)
test
rowMeans(test)
apply(test,1,function(y)mean(y>=0))

Is there anything wrong?
thanks,

Yes!!!

It's mean( y[y >= 0] )

Rui Barradas

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Sorry, my mistake.

it works very well!!!

thanks,

Rui Barradas wrote
Hello,

york8866 wrote
Hi, John,

the code ran well.

however, somehow, the means were not calculated correctly using the
following code.

test <- read.csv("Rtestdataset.csv", as.is=T,header=T)  
test <- data.frame(test)
test
rowMeans(test)
apply(test,1,function(y)mean(y>=0))

Is there anything wrong?
thanks,

Yes!!!

It's mean( y[y >= 0] )

Rui Barradas

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