I have 1000 candidate genes with their expression (FPKM). I would like to test the gene-expression difference between two groups of Individuals with heart_Failure and normal. In the linear model I have some covariates like "age", "sex", "BMI" and "Hypertension", however there are some missing values (NA) in the covariate file. I created the design matrix as follows:
design <- model.matrix(~age+sex+BMI+ Hypertension+group) ; Note: group (No=normal , Yes=heart_Failure)
after I run the linear model as: fit <- lmFit(expression,design), It gave me an error because of some missing values in the model. How to fix this problem?
All values in "expression" and "group" are complete (no-missing), just I have missing values in covariables. How to fix this issue. Could you please advise by sending an example. Thank you