Help with setting DimPlot UMAP output into a 2x3 grid in Seurat
how to get this to arrange the UMAP plots into a 2x3 grid

You can use the ncol parameter, which will set the number of columns in the &quot;combined plot&quot;.
And for future reference, if you get the help page of the function you are using with ?DimPlot, you will see the .... This means that you can feed additional arguments to other functions that DimPlot() uses. Apparently,  CombinePlots() is used under the hood and has an ncol parameter.