[R] different results in MASS's mca and SAS's corresp

[Gong-Yi Liao]

Dear list:

   I have tried MASS's mca function and SAS's PROC corresp on the 
   farms data (included in MASS, also used as mca's example), the 
   results are different:

   R: mca(farms)$rs:
              1             2
1   0.059296637  0.0455871427
2   0.043077902 -0.0354728795
3   0.059834286  0.0730485572
4   0.059834286  0.0730485572
5   0.012900181 -0.0503121890
6   0.038846577 -0.0340961617
7   0.005886752 -0.0438516465
8  -0.015108789 -0.0247221783
9   0.007505626 -0.0646608108
10  0.006631230 -0.0362117073
11  0.013309217 -0.0680733730
12  0.056549933  0.0010773359
13  0.015681958  0.0334320046
14 -0.065598990  0.0151619769
15 -0.046868229  0.0357782553
16 -0.003048803  0.0128157261
17 -0.051281437  0.0278941743
18 -0.051819085  0.0004327598
19 -0.072814626  0.0195622280
20 -0.072814626  0.0195622280

      And in SAS's corresp output:

                                Row Coordinates

                                        Dim1       Dim2

                          1           1.0607    -0.8155
                          2           0.7706     0.6346
                          3           1.0703    -1.3067
                          4           1.0703    -1.3067
                          5           0.2308     0.9000
                          6           0.6949     0.6099
                          7           0.1053     0.7844
                          8          -0.2703     0.4422
                          9           0.1343     1.1567
                         10           0.1186     0.6478
                         11           0.2381     1.2177
                         12           1.0116    -0.0193
                         13           0.2805    -0.5980
                         14          -1.1735    -0.2712
                         15          -0.8384    -0.6400
                         16          -0.0545    -0.2293
                         17          -0.9174    -0.4990
                         18          -0.9270    -0.0077
                         19          -1.3025    -0.3499
                         20          -1.3025    -0.3499

        
        Is MASS's mca developed with different definition to SAS's 
        corresp ?

        Thank you for any comments!




-- 
Gong-Yi Liao

Department of Statistics
University of Connecticut
215 Glenbrook Road  U4120
Storrs, CT 06269-4120

860-486-9478