On 11/5/2014 5:41 AM, Noha Osman wrote:
Hi Folks
Iam a new user of R and I have a question . Hopefully anyone help me in that
issue
I have that dataset as following
Sample Population Species Tissue R G B
1 Bari1_062-1 Bari1 ret seed 94.52303 80.70346 67.91760
2 Bari1_062-2 Bari1 ret seed 98.27683 82.68690 68.55485
3 Bari1_062-3 Bari1 ret seed 100.53170 86.56411 73.27528
4 Bari1_062-4 Bari1 ret seed 96.65940 84.09197 72.05974
5 Bari1_062-5 Bari1 ret seed 117.62474 98.49354 84.65656
6 Bari1_063-1 Bari1 ret seed 144.39547 113.76170 99.95633
and I have 20 populations as following
[1] Bari1 Bari2 Bari3 Besev Cermik Cudi Derici
Destek Egil
[10] Gunasan Kalkan Karabace Kayatepe Kesentas Ortanca Oyali
Cultivated Sarikaya
[19] Savur Sirnak
I need to calculate mean and variance of each population using column [R] using
for-loop
Thanks
You don't want to use loops here, but rather some vectorized function.
One possibility is some thing like the following:
with(your_data_frame,aggregate(R,list(Population), mean))
with(your_data_frame,aggregate(R,list(Population), var))
hope this is helpful,
Dan
Daniel Nordlund
Bothell, WA USA
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