Stata 15 help for anovadef

Title

[P] anovadef -- anova and manova term definition programming command

Syntax

anovadef [, alt | showorder]

Description

anovadef returns in r() a labeling of the coefficients from the last anova or manova. It numbers the returned values in the same order they are presented in the e(b) and e(V) matrices from the anova or manova. This is helpful since the order of the coefficients in e(b) or in e(V) is not always the same as the order specified in the anova or manova command, and when the anova or manova was run under version less than 11, the matrix row and column names are not meaningful.

For manova, the labeling for one equation is returned. This same labeling applies to each of the equations. The equation names are already attached to the e(b) and e(V) matrices, and so anovadef does not return them.

Options

alt specifies an alternate way of returning the labeling information; see remarks below.

showorder specifies that instead of executing silently, anovadef is to display the design matrix column definitions and not return results in r(). showorder may not be specified with alt.

Remarks

After the following anova

. version 10: anova wei len rep*for len*for for rep*len rep rep*len*for*gea, cont(gea len)

anovadef without the alt option

. anovadef

produces results named r(tid#) where # goes from 1 to the number of elements in e(b). tid stands for "term id".

Here are a few of the r() items produced with the example above:

r(tid1) : "1" r(tid2) : "length" r(tid3) : "(foreign==0)" r(tid4) : "(foreign==1)" r(tid5) : "(rep78==1)" r(tid6) : "(rep78==2)" r(tid7) : "(rep78==3)" r(tid8) : "(rep78==4)" r(tid9) : "(rep78==5)" r(tid10) : "(rep78==1)*(foreign==0)" r(tid11) : "(rep78==2)*(foreign==0)" r(tid12) : "(rep78==3)*(foreign==0)" ... r(tid29) : "(rep78==4)*length*(foreign==0)*gear_ratio" r(tid30) : "(rep78==4)*length*(foreign==1)*gear_ratio" r(tid31) : "(rep78==5)*length*(foreign==0)*gear_ratio" r(tid32) : "(rep78==5)*length*(foreign==1)*gear_ratio"

r(tid1) corresponds to the constant and is simply "1". This is how anovadef indicates the constant.

anovadef with the alt option

. anovadef, alt

produces results named r(tn#) and r(tl#) where # goes from 1 to the number of elements in e(b). tn stands for "term names" and tl stands for "term levels".

Here are a few of the r() items produced with the example above:

r(tn1) : "1" r(tl1) : "c" r(tn2) : "length" r(tl2) : "c" r(tn3) : "foreign" r(tl3) : "0" r(tn4) : "foreign" r(tl4) : "1" r(tn5) : "rep78" r(tl5) : "1" r(tn6) : "rep78" r(tl6) : "2" r(tn7) : "rep78" r(tl7) : "3" r(tn8) : "rep78" r(tl8) : "4" r(tn9) : "rep78" r(tl9) : "5" r(tn10) : "rep78 foreign" r(tl10) : "1 0" r(tn11) : "rep78 foreign" r(tl11) : "2 0" r(tn12) : "rep78 foreign" r(tl12) : "3 0" ... r(tn29) : "rep78 length foreign gear_ratio" r(tl29) : "4 c 0 c" r(tn30) : "rep78 length foreign gear_ratio" r(tl30) : "4 c 1 c" r(tn31) : "rep78 length foreign gear_ratio" r(tl31) : "5 c 0 c" r(tn32) : "rep78 length foreign gear_ratio" r(tl32) : "5 c 1 c"

A "c" indicates that the corresponding term is a continuous variable. A number indicates that it is a categorical variable.

anovadef with the showorder option displays the following output.

. anovadef, showorder

Order of columns in the design matrix 1: _cons 2: length 3: (foreign==0) 4: (foreign==1) 5: (rep78==1) 6: (rep78==2) 7: (rep78==3) 8: (rep78==4) 9: (rep78==5) 10: (rep78==1)*(foreign==0) 11: (rep78==2)*(foreign==0) 12: (rep78==3)*(foreign==0) 13: (rep78==3)*(foreign==1) 14: (rep78==4)*(foreign==0) 15: (rep78==4)*(foreign==1) 16: (rep78==5)*(foreign==0) 17: (rep78==5)*(foreign==1) 18: (rep78==1)*length 19: (rep78==2)*length 20: (rep78==3)*length 21: (rep78==4)*length 22: (rep78==5)*length 23: length*(foreign==0) 24: length*(foreign==1) 25: (rep78==1)*length*(foreign==0)*gear_ratio 26: (rep78==2)*length*(foreign==0)*gear_ratio 27: (rep78==3)*length*(foreign==0)*gear_ratio 28: (rep78==3)*length*(foreign==1)*gear_ratio 29: (rep78==4)*length*(foreign==0)*gear_ratio 30: (rep78==4)*length*(foreign==1)*gear_ratio 31: (rep78==5)*length*(foreign==0)*gear_ratio 32: (rep78==5)*length*(foreign==1)*gear_ratio


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