getting rid of certain rows in a matrix

[spencer keene]

Hello All, Probably a fairly simple question but I still can't figure this out. Suppose you have the following: mat A = (2,1\3,2\-2,2) mat B = (1,1\3,4\5,0) mat C = A,B\B,A mat list C C[6,4] c1 c2 c1 c2 r1 2 1 1 1 r2 3 2 3 4 r3 -2 2 5 0 r1 1 1 2 1 r2 3 4 3 2 r3 5 0 -2 2 But what if I want to get rid of all of the 'r1' rows? How can I do this? Thanks for your help.

[Clyde Schechter]

-help matrix extraction-

[Nick Cox]

My best tip is to work in Mata if you want matrix manipulation.

Otherwise various community-contributed add-ons to Stata's matrix language were published around 25 years ago. .

STB-56 dm79 . . . . . . . . . . . . . . . . . . Yet more new matrix commands
(help matcorr, matewmf, matvsort, svmat2 if installed) . . N. J. Cox
7/00 pp.4--8; STB Reprints Vol 10, pp.17--23
commands to produce a correlation matrix, elementwise monadic
function of another matrix, selected subsets of matrix rows
and columns, vec or vech of a matrix, elements sorted within
a vector, matrix from a vector, and commands to save matrices
see mata matrix language incorporated into Stata 9.0


STB-50 dm69 . . . . . . . . . . . . . . . . . . Further new matrix commands
(help matdelrc, matewm, matmad, matpow if installed) . . . N. J. Cox
7/99 pp.5--9; STB Reprints Vol 9, pp.29--34
collection of new matrix commands providing additional matrix
checking, management, element-wise operators, maximum absolute
difference, and power

STB-39 dm49 . . . . . . . . . . . . . . . . . . . . Some new matrix commands
(help matfunc, varfunc if installed) . . . . . . . . . . . J. Weesie
9/97 pp.17--20; STB Reprints Vol 7, pp.43--48
collection of new matrix commands; several for explicit matrices
and a few for implicit matrices (i.e., variables)
see mata matrix language incorporated into Stata 9