Hi,

I have 16 variables/columns, and I'm trying to make a histogram for all of them at once to explore normality. The variables are all numeric which I have confirmed in R. However with my code below it gives me the above error.

hist(Dar[,c(uco_ugl,uni_ugl, uzn_ugl, ucu_ugl, usr_ugl, umo_ugl, ucs_ugl, uba_ugl, uhg_ugl, upb_ugl, uv_ugl, ucr_ugl, umn_ugl, ufe_ugl, use_ugl, uas_ugl, ucd_ugl)])

Could someone please help?

Thanks!