Using time series (two condition with 4 time point) data in DESeq2, i got warning while fitting by GLM ??
bckCDS <- DESeqDataSetFromMatrix(countData = x, colData=ExpDesign, design= ~condition.label + condition.Time + condition.label:condition.Time)
> ddsLRT= DESeq (bckCDS, test ="LRT", reduced = ~condition.label + condition.Time)
estimating size factors
gene-wise dispersion estimates
NOTE: fitType='parametric', but the dispersion trend was not well captured by the
function: y = a/x + b, and a local regression fit was automatically substituted.
specify fitType='local' or 'mean' to avoid this message next time.
final dispersion estimates
fitting model and testing
May i have fit it by "local", indeed its work by this however, my question is why its not working by "fitType='parametric'". What is advantage and disadvantage of it.