{smcl} {* 25aug2008}{...} {cmd:help mata mz_stdc()} {hline} {title:Title} {p 4 14 2} {bf:mz_stdc() -- Calculates the standard deviation of each column of a matrix} {title:Syntax} {p 4 23 2} {it:real matrix} {cmd:mz_stdc(}{it:x}{cmd:)} {pstd} where {p 12 16 2} {it:x}: {it:real matrix} {title:Description} {p 4 4 2} {cmd:mz_stdc()} computes the standard deviation of each column of a matrix and puts the result in a column vector. {title:Remarks} {pstd} Example: {com}: x {res} {txt}1 2 3 4 {c TLC}{hline 17}{c TRC} 1 {c |} {res}1 3 5 6{txt} {c |} 2 {c |} {res}4 3 2 1{txt} {c |} 3 {c |} {res}7 5 3 2{txt} {c |} 4 {c |} {res}8 9 0 1{txt} {c |} 5 {c |} {res}4 6 8 9{txt} {c |} 6 {c |} {res}3 2 6 7{txt} {c |} 7 {c |} {res}1 4 5 7{txt} {c |} 8 {c |} {res}7 2 4 6{txt} {c |} 9 {c |} {res}1 4 0 3{txt} {c |} 10{c |} {res}1 4 6 7{txt} {c |} {c BLC}{hline 17}{c BRC} {com}: mz_stdc(x) {res} {txt} 1 {c TLC}{hline 15}{c TRC} 1 {c |} {res}2.790858092{txt} {c |} 2 {c |} {res}2.097617696{txt} {c |} 3 {c |} {res}2.643650675{txt} {c |} 4 {c |} {res}2.884826203{txt} {c |} {c BLC}{hline 15}{c BRC} {title:Conformability} {cmd:mz_stdc(}{it:x}{cmd:)} {it:x}: {it:r x c} {it:result}: {it:c x 1}. {title:Diagnostics} {p 4 4 2} {cmd:mz_stdc()} returns an empty column vector if {it:x} is a row vector. In addition, to compute the standard deviations, {cmd:mz_stdc()} uses N-1 rather than N as divisor, where N is the number of rows of matrix {it:x}. To convert to the alternate definition, multiply the output of {cmd:mz_stdc()} by sqrt((N-1)/N). {title:Source code} {p 4 4 2} {help ltimbimata_source##mz_stdc:mz_stdc.mata} {title:Author} {p 4 4 2} Diallo Ibrahima Amadou, {browse "mailto:zavren@gmail.com":zavren@gmail.com} {title:Also see} {p 4 13 2} Online: help for {bf:{help mf_variance:[M-5] variance()}}, {bf:{help ltimbimata}} {p_end}