Extracting elements from matrix

[Roman Mostazir]

Hi,
Is there any way of extracting specific information from a matrix. For example:

sysuse auto, clear

qui reg price mpg weight
mat m =r(table)'

mat li m

m[3,9]
                 b          se           t      pvalue          ll          ul          df        crit       eform
   mpg  -49.512221   86.156039  -.57468079   .56732373  -221.30248   122.27804          71   1.9939434           0
weight   1.7465592   .64135379   2.7232382   .00812981   .46773602   3.0253823          71   1.9939434           0
 _cons   1946.0687   3597.0496   .54101802   .59018863  -5226.2445   9118.3819          71   1.9939434           0

mat myelement = m[1, 1 .. 3]
mat li myelement

myelement[1,3]
              b          se           t
mpg  -49.512221   86.156039  -.57468079

Until now this is fine. But is there any way to extract only 1st, 3rd and 5th elements of first row rather using a range?

Thanks.

[Steve Samuels]

 mat list A

    c1  c2  c3
r1   1   2   3
r2   4   5   6

. mat B = A[1,1],A[1,3]

. mat list B

B[1,2]
    c1  c2
r1   1   3

[Roman Mostazir]

Thanks Steve, very helpful.

[Steve Samuels]

You're welcome, Roman. You can also use column and row names with this method

. mat list A

A[2,3]
       red   green  yellow
r1       1       2       3
r2       4       5       6

. mat B= A[1,"red"],A[1,"yellow"]

. mat list B

B[1,2]
       red  yellow
r1       1       3

[Roman Mostazir]

Thanks again Steve. Another question, how to show the full row/column names and avoid truncation, such as the one below:

mat A = 1,2,3\4,5,6
mat colnames A= redbrickhouse greengrasshouse yellowwallhouse
mat rownames A= myhousenumers yourhousenumbers
mat li A

A[2,3]
              redbrickho~e  greengrass~e  yellowwall~e
myhousenum~s             1             2             3
yourhousen~s             4             5             6

[Steve Samuels]

Try the matlist command.