I have measured events X and Y in two strains (A and B) of same species. After calculating the values of these X and Y, I compared them with wild type values (X and Y) to calculate fold change. I have plotted these fold changes of X and Y in A and B, and curve was fitted with LOESS.
Now for event X (top plot) LOESS approximates to straight line, but for event Y (bottom plot), the smaller values (Chromosome size < 600 kb) seem to be elevated.
My question is by just showing this plot can I claim that smaller chromosomes get more event-Y than larger chromosomes (chromosome size > 600 kb) or do I need to do statistical tests to say this ?? If so what tests do you suggest ?
Sorry I am poor when it comes to advanced statistics. Hope I have clearly stated my problem.
Best Answer
Welcome to the site.
You can say that smaller chromosomes get more Y-event than larger ones based on this graph; if you want to say that they get significantly more then you need some sort of statistical test.
If you are using
R
then therms
package offers tests of splines and loess fits.If you are using
SAS
there isPROC LOESS
.Several interesting things seem to be going on in your two graphs; you didn't ask about this, but did you note that for X, the A curve is higher and for Y the B curve is? This might be interesting.