FACTOR: Improve calculation of Kaiser-Meyer-Olkin and add a test

diff --git a/src/language/stats/factor.c b/src/language/stats/factor.c
index a1cd333389c7276bc5a6ed7c37b776f2daf583a1..095d98ff35c5c0c290bae9cc3c6ab45f1fdd9afb 100644 (file)
--- a/src/language/stats/factor.c
+++ b/src/language/stats/factor.c
@@ -293,7 +293,7 @@ ssq_row_od_n (const gsl_matrix *m, int j)
   return ss;
 }
 
-/* Return the sum of all the elements excluding row N */
+/* Return the sum of squares of all the elements excluding row N */
 static double
 ssq_od_n (const gsl_matrix *m, int n)
 {
@@ -305,9 +305,9 @@ ssq_od_n (const gsl_matrix *m, int n)
 
   for (i = 0; i < m->size1; ++i)
     {
-      if (i == n ) continue;
       for (j = 0; j < m->size2; ++j)
        {
+         if (i == j) continue;
          ss += pow2 (gsl_matrix_get (m, i, j));
        }
     }
@@ -2384,8 +2384,8 @@ do_factor_by_matrix (const struct cmd_factor *factor, struct idata *idata)
   double sum_ssq_a = 0;
   for (i = 0; i < r_inv->size1; ++i)
     {
-      sum_ssq_r += ssq_od_n (r_inv, i);
-      sum_ssq_a += ssq_od_n (idata->ai_cov, i);
+      sum_ssq_r += ssq_od_n (idata->mm.corr, i);
+      sum_ssq_a += ssq_od_n (idata->ai_cor, i);
     }
 
   gsl_matrix_free (r_inv);

diff --git a/tests/language/stats/factor.at b/tests/language/stats/factor.at
index 38dcd50f595c82bcbde6fd6992b1235403f9f0a9..7cf1718b83067840884d81d27453f9bea3702684 100644 (file)
--- a/tests/language/stats/factor.at
+++ b/tests/language/stats/factor.at
@@ -2094,18 +2094,12 @@ end data.
 
 factor matrix in (cov = *)
     / method = covariance
-    / print = initial covariance kmo
+    / print = initial covariance
     / extraction = pc
     / rotation = norotate.
 ])
 
 AT_CHECK([pspp -O format=csv covariance-matrix.sps], [0], [dnl
-Table: KMO and Bartlett's Test
-Kaiser-Meyer-Olkin Measure of Sampling Adequacy,,.741
-Bartlett's Test of Sphericity,Approx. Chi-Square,104.810
-,df,28
-,Sig.,.000
-
 Table: Covariance Matrix
 ,var01,var02,var03,var04,var05,var06,var07,var08
 var01,32.490,1.539,-29.469,11.902,4.309,8.464,15.390,1.454
@@ -2342,3 +2336,50 @@ ran,.592,.262,-.069,-.638,.096
 ])
 
 AT_CLEANUP
+
+
+AT_SETUP([FACTOR Kaiser-Meyer-Olkin])
+
+AT_DATA([kmo.sps], [dnl
+SET FORMAT=F20.3 .
+matrix data
+ variables = rowtype_ viq piq pa ran piatwr  piatc
+ / n = 476
+ / format = lower diagonal .
+begin data
+mean  96.88  100.51  -1.73  -0.94  -2.52 -1.85
+sd    10.97   11.19   1.19   0.88   0.85  0.97
+corr    1.00
+corr    0.38  1.00
+corr    0.26  0.24  1.00
+corr    0.16  0.17  0.34  1.00
+corr    0.25  0.07  0.46  0.38  1.00
+corr    0.37  0.22  0.39  0.30  0.59   1.00
+end data.
+
+factor matrix = in (cor = *) 
+ / analysis = viq piq pa ran piatwr piatc
+ / extraction = pc
+ / rotation = norotate
+ / print = kmo
+])
+
+AT_CHECK([pspp -O format=csv kmo.sps], [0], [dnl
+Table: KMO and Bartlett's Test
+Kaiser-Meyer-Olkin Measure of Sampling Adequacy,,.730
+Bartlett's Test of Sphericity,Approx. Chi-Square,602.673
+,df,15
+,Sig.,.000
+
+Table: Component Matrix
+,Component,,,,
+,1,2,3,4,5
+viq,.589,-.539,.033,.298,.457
+piq,.456,-.733,.122,-.289,-.377
+pa,.707,.124,-.117,-.161,.256
+ran,.592,.262,-.069,-.638,.096
+piatwr,.754,.418,.442,.219,-.115
+piatc,.774,.122,-.368,.365,-.322
+])
+
+AT_CLEANUP