stat/mds: make TorgersonScaling tests pass on arm64
The failure is due to ED instability around zero.
MODIFY
stat/mds/mds_test.go
stat/mds/mds_test.go
package mds
import (
+ "math"
"testing"
"gonum.org/v1/gonum/floats"
@@ -16,6 +17,7 @@ var torgersonScalingTests = []struct {
wantK int
want *mat.Dense
wantVals []float64
+ tol float64
}{
// All expected values obtained from running R cmdscale with the input here.
{
@@ -45,6 +47,7 @@ var torgersonScalingTests = []struct {
1.172027697614e+07, 5.686036184502e+06, 2.474981412369e+04, 1.238300279584e+03,
-5.444455825182e-10, -2.471028925712e+02, -2.412961483429e+03, -8.452858567111e+04,
},
+ tol: 1e-9,
},
{
// R eurodist dataset.
@@ -106,12 +109,13 @@ var torgersonScalingTests = []struct {
-3.326719007160e+05, -5.162522542344e+05, -9.191490984121e+05, -1.006503960172e+06,
-2.251844331736e+06,
},
+ tol: 1e-9,
},
}
func TestTorgersonScaling(t *testing.T) {
for i, test := range torgersonScalingTests {
- _, c := test.dis.Dims()
+ r, c := test.dis.Dims()
var got mat.Dense
gotK, gotVals := TorgersonScaling(&got, make([]float64, c), test.dis)
if gotK == 0 {
@@ -119,13 +123,24 @@ func TestTorgersonScaling(t *testing.T) {
continue
}
if gotK != test.wantK {
+ var derivedK int
+ for derivedK = range gotVals {
+ if math.Abs(gotVals[derivedK]) < test.tol {
+ got = *got.Slice(0, r, 0, derivedK).(*mat.Dense)
+ break
+ }
+ }
+ if derivedK != test.wantK {
t.Errorf("unexpected k for test %d: got:%d want:%d", i, gotK, test.wantK)
+ } else {
+ t.Logf("low precision (tol=%.0e) k for test %d: gotK:%d derived=want:%d", test.tol, i, gotK, test.wantK)
+ }
}
- if !mat.EqualApprox(colAbs{&got}, colAbs{test.want}, 1e-5) {
+ if !mat.EqualApprox(colAbs{&got}, colAbs{test.want}, math.Sqrt(test.tol)) {
t.Errorf("unexpected result for test %d:\ngot:\n%.5f\nwant:\n%.5f",
i, mat.Formatted(&got), mat.Formatted(test.want))
}
- if !floats.EqualApprox(gotVals, test.wantVals, 1e-10) {
+ if !floats.EqualApprox(gotVals, test.wantVals, test.tol) {
t.Errorf("unexpected Eigenvalues for test %d:\ngot: %.12e\nwant:%.12e", i, gotVals, test.wantVals)
}
}

stat/mds: make TorgersonScaling tests pass on arm64

The failure is due to ED instability around zero.