[R] Calculating the mean in one column with empty cells

[David Winsemius]

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