Clustering Calibration Data for Calculations in a Matrix

Hello,

I have a matrix that has concentration of the sample in row one, versus instrument response in row two. The instrument response was measured several times at the same concentration. For example:

1 4.5

1 4.4

1 4.6

2 9.0

2 9.1

2 9.2

3 18

3 18

3 18

I want to form a new matrix that clusters the row two data like:

4.5 9 18

4.4 9.1 18

4.6 9.2 18

so that I can then calculate the standard deviation of each new row:

sd(4.5, 4.4, 4.6)

and so on. This way I get a standard deviation for concentration 1, concentration 2, and concetration 3, and on. I am doing this manually now, but would like help automating it.

Thank you!

Answer 1

[Steven Lord]

I'd just use the groupsummary function.