Calculating the mean in one column with empty cells

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
Of David Winsemius
Sent: Saturday, October 06, 2012 9:08 AM
To: fxen3k
Cc: r-help at r-project.org
Subject: Re: [R] Calculating the mean in one column with empty cells


On Oct 6, 2012, at 1:11 AM, fxen3k wrote:

Hi,

the first command was bringing the numbers into R directly:
*> testdata <- c(0.2006160108532920, 0.1321167173880490, 0.0563941428921262,
0.0264198664609803, 0.0200581303857603, -0.2971754213679500,
-0.2353086361784190, 0.0667195538296534, 0.1755852636926560)

mean(testdata)

[1] 0.0161584*

Here I tried to calculate the mean with the same numbers as given above, but
taken from my dataset.
*

str(dataSet2$ac_bhar_60d_4d_after_ann[1:9])

num [1:9] 0.2 0.13 0.06 0.03 0.02 -0.3 -0.24 0.07 0.18

mean(dataSet2$ac_bhar_60d_4d_after_ann[1:9])

[1] 0.01666667
*

This is something that has happened in data processing:

dat <- read.csv2(text="0,2006160108532920

+ 0,1321167173880490
+ 0,0563941428921262
+ 0,0264198664609803
+ 0,0200581303857603
+ -0,2971754213679500
+ -0,2353086361784190
+ 0,0667195538296534
+ 0,1755852636926560
+ ", header=FALSE)

mean(dat[[1]])

[1] 0.0161584

It seems that in the second case he calculates the mean with rounded numbers
(0.2 and not 0.20061601085...)
Could it be that R imports only the rounded numbers?
How can I build a CSV-file with numbers showing all decimal places? Because
I think my current CSV-file only has numbers with 2 decimal places.

That is more likely the fault of Excel than it is something R is responsible for.

--

David Winsemius, MD
Alameda, CA, USA