Example input for multiple genes:
                1007_s_at 1
                200000_s_at -1 
                31637_s_at 0.5 
                40016_g_at -2
            
            
                Explanation: 
                first: normal,
                second: gene is inverted,  
                third: gene has weight,  
                fourth: gene has weight and is inverted
            
            
                You can also use following format: 
                1007_s_at, 1 
                200000_s_at, -1 
                31637_s_at, 0.5 
                40016_g_at, -2