Accuracy issue in float
In test_dimension the accuracy is bad in float for 1d and 3d data.
1d ./examples/RelWithDebInfo/test_dimension --input-file ../units/fmm/test_1d_ref.fma -th 4 -gs 2 --d 1 --order 2 Ordre. L2-norm 1 0.00484234 2. 0.00484234 3. 0.00484234 …
./examples/RelWithDebInfo/test_dimension --input-file ../units/fmm/test_2d_ref.fma -th 4 -gs 2 --d 2 --order 3 2d 100 particules 1 0.00775739 2. 0.00273968 3. 0.000584938 4 9.08979e-05 5 1.86704e-05 7 6.96384e-06
./examples/RelWithDebInfo/test_dimension --input-file ../units/fmm/test_3d_ref.fma -th 4 -gs 2 --d 3 --order 3 3d 100 particules 1 0.99997 2. 0.99997 3. 0.99997 4 0.99997 5 0.99997 7 0.99997