# building and analyzing a regression model

I'm trying build a model to predict sells of clothe store for each cluster to month 11 and 12.

I've 98 stores, and for each store i have this data, but i put the all data to calc only 1 model.

I use R to calc the model, and i have this "Coefficients: (1 not defined because of singularities)" the coefficent is S11. i've already read that it happens because there is correlation between the variables, but i dont know how fix it or if my model is correctly created.

thank you so much!

competition is the level on competition where the store are located (1= low 2=medium 3 = high)

Cluster = 1,2,3,4,5 depends which cluster the store belongs.

S01, S02, S03 ....S11 is the dummies for sazonality. Year, 1= 2015 and 2=2016 Obs= Observation number

• Please explain what the data mean. Where are the sales? – whuber Nov 14 '16 at 19:42
• i did not add the Sales in the picture, because i thougth that was not necessary. – CFC Nov 14 '16 at 19:57
• I believe it is crucial to explain your data, because your data appear to form a singular matrix (as R has explained) and we cannot provide objective, reasoned recommendations about how to deal with that unless we can understand what the data are intended to mean. – whuber Nov 14 '16 at 20:00
• competition is the level on competition where the store are located (1= low 2=medium 3 = high) Cluster = 1,2,3,4,5 depends which cluster the store belongs. S01, S02, S03 ....S11 is the dummies for sazonality. Year, 1= 2015 and 2=2016 Obs= Observation number Thank you – CFC Nov 14 '16 at 20:02