{smcl} {* 16jul2020}{...} {cmd:help mata mm_isconstant()} {hline} {title:Title} {pstd} {bf:mm_isconstant() -- Whether matrix is constant or whether vector is sorted} {title:Syntax} {p 8 20 2} {it:real scalar}{bind: } {cmd:mm_isconstant(}{it:X}{cmd:)} {p 8 20 2} {it:real scalar}{bind: } {cmd:mm_issorted(}{it:x} [{cmd:,} {it:descending}]{cmd:)} {p 4 8 2} where {p 14 18 2}{it:X}: {it:transmorphic matrix X} {p_end} {p 14 18 2}{it:x}: {it:numeric vector x} or {it:string vector x} {p_end} {p 5 18 2}{it:descending}: {it:real scalar} requesting descending order {p_end} {title:Description} {pstd}{cmd:mm_isconstant()} returns 1 if all elements in {it:X} are equal and returns 0 otherwise. {it:X} can be any kind. {pstd}{cmd:mm_issorted()} returns 1 if the elements in vector {it:x} are sorted and returns 0 otherwise. {it:x} can be numeric or string. Specify {it:descending}!=0 to check for descending sort order. The default is to check for ascending sort order. {title:Remarks} {pstd}None. {title:Diagnostics} {pstd}{cmd:mm_isconstant()} returns 1 if {it:X} is void. {pstd}{cmd:mm_issorted()} returns 1 if {it:x} is void. {title:Source code} {pstd} {help moremata_source##mm_isconstant:mm_isconstant.mata} {title:Author} {pstd} Ben Jann, University of Bern, ben.jann@soz.unibe.ch {title:Also see} {psee} Online: help for {bf:{help mf_sort:[M-4] sort}}, {bf:{help mf_mm_sort:mm_sort}}, {bf:{help m4_utility:[M-4] utility}}, {bf:{help moremata}} {p_end}