plot with grouping variables

Hi there!

I’m a beginner in working with matlab but maybe someone knows how to deal with this.

I want to plot a few selected graphs out of the following matrix (small example):

dose PT conc
1 0 2.73
1 7 29.81
2 0 2.78
2 7 24.77
…. …. …..

Therefore the concentration should be plotted semilogarithmic against PT and the graphs should be grouped by the various doses (I have about 30 various dosing regimes with 10 times respectively). For the plot I want to select only a few graphs say dose 1 and 2 and not all the available ones.
Using the command ‘gscatter' I can group my concentrations by dose but I need to plot a real graph rather than a scatter.

Please help me!!!