I need to do some statistical calculation on CNV data that is publicly available in TCGA website. I am from computer background and no idea about the meaning of these data. I tried searching for the meaning of the files, how they are structured and all but nothing was helpful. It would be nice if someone could give a short overview of the meaning of data in each column. A sample of data present in a CNV file
Sample Chromosome Start End Num_Probes Segment_Mean DEBUT_p_TCGAb45_81_wRedosSNP_N_GenomeWideSNP_6_G03_729530 1 61735 415164 28 -0.0504 DEBUT_p_TCGAb45_81_wRedosSNP_N_GenomeWideSNP_6_G03_729530 1 462793 629241 4 1.822 DEBUT_p_TCGAb45_81_wRedosSNP_N_GenomeWideSNP_6_G03_729530 1 668210 2138242 350 -0.0311
So I want to know what is the underlying meaning of sample, how they are named. Sample name seems always a big name. Then I understand the columns chromosome, start and end. But I don't understand the meaning of Num_probes and Segmentation_mean?