The results below indicate that
(1) One can extract a cell from a matrix using the row and column names, but
(2) the value returned cannot be assigned to a scalar, only to a
one-by-one matrix. (See error below.)
(3) By contrast, when one extracts a cell from a matrix using row and
column *indices*, the value can be assigned to a scalar.
Is there some good reason for this? I'd ideally like to extract a
scalar by row and column name, since this would be less error-prone.
Thanks for any insights
. mat lis Betas3
Betas3[8,4]
glmeFixed margOverYear margOverNAME margOverBOTH
Intercept 1.076851 1.0446041 .9314962 .91146427
Sex01F -.10872187 -.10572026 -.09461439 -.09260798
PL2Age2 -.0382385 -.03690922 -.03247097 -.03172728
Sex01FxPL2Age2 -.04284441 -.04173549 -.03758942 -.0368254
PL2Age3 -.09794232 -.0954067 -.08586944 -.08411177
MinCC -.05824123 -.05666053 -.05079008 -.04972423
PzCDrp -.29371127 -.28608519 -.25737673 -.2520895
MinCCxPzCDrp -.03753782 -.03658906 -.03301933 -.03235626
. matrix tryThis=Betas3["Intercept","margOverBOTH"]
. mat lis tryThis
symmetric tryThis[1,1]
margOverBOTH
Intercept .91146427
. scalar tryThis2=Betas3["Intercept","margOverBOTH"]
matrix operators that return matrices not allowed in this context
r(509);
. scalar tryThis2=Betas3[1,4]
. di "tryThis2=" tryThis2
tryThis2=.91146427
. matrix tryThis3=Betas3[1,4]
. mat lis tryThis3
symmetric tryThis3[1,1]
c1
r1 .91146427
Jacob A. Wegelin
Assistant Professor
Department of Biostatistics
Virginia Commonwealth University
730 East Broad Street Room 3006
P. O. Box 980032
Richmond VA 23298-0032
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