I will use a genechip indentified by GSE4330m GEO(http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi). However the GSE1133 has 3 platforms:GPL81,GPL82,GPL83,it has 21 samples every platform.if the GPL81 has a gene (7157) which is not including in GPL82 and the GPL82 has a gene (7156) which is not including in GPL81 ,however GPL83 has both of them ,how can i caculate the pearson coefficient between the gene 7157 and 7156? [[alternative HTML version deleted]]

On Tue, Sep 9, 2008 at 5:03 AM, jiabao xu <xujiabao127 at="" gmail.com=""> wrote: > I will use a genechip indentified by GSE4330m > GEO(http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi). > > However the GSE1133 has 3 platforms:GPL81,GPL82,GPL83,it has 21 samples > every platform.if the GPL81 has a gene (7157) which is not including in > GPL82 and the GPL82 has a gene (7156) which is not including in > GPL81 ,however GPL83 has both of them ,how can i caculate the pearson > coefficient > between the gene 7157 and 7156? You can use the cor() function to calculate the correlation between two vectors. Since you have two measurements (at least) for each gene, you can get multiple correlations. Perhaps you can show us the code that you have used to get the data and where you are having problems calculating the correlation, as it isn't clear where you are having problems. Sean