# NUL Fabric tensor values in Anisotropy BoneJ

Good day,

I read with a lot of interest the following thread from which I could safe the information that the tensors vector from the smallest tenseur value could give the general preferential orientation.

Then I realized that the Fabric tensor values that I get in the result tab from Anisotropic were either nul or equal to one bu I still had a degree of Anisotropy (0,392)

Fabric tensor vectors

``````|| 0.629| 0.772|-0.094||
||-0.167| 0.016|-0.986||
|| 0.759|-0.636|-0.139||
``````

Fabric tensor values

``````||0.000|0.000|0.000||
||0.000|0.000|0.000||
||0.000|0.000|0.000||
``````
``````1	min5voxels	0.392	1.644	0.629	0.772	-0.094	-0.167	0.016	-0.986	0.759	-0.636	-0.139	1.302E-4	1.568E-4	2.140E-4
``````

It is also true that the ellipsoĂŻde is almost a sphere

Could you tell me what is going on with the Fabric tensor values ?

I study x-ray ÂµCT tomography soil images.

Perhaps @mdoube or @rimadoma would be able to assist you in this?

eta

Itâ€™s not - if spherical it would look like a circle in this view, but I see an ellipse with its long axis at ~10 oâ€™clock - 4 oâ€™clock

DA is calculated as 1 - (smallest / largest eigenvalue).

The eigenvalues are reported here:

So in this example DA = 1 - 1.302E-4 / 2.140E-4 = 0.392

(the code that does this calculation is here)

The â€śfabric tensor valuesâ€ť reported in the log window are not particularly helpful when they get small, because itâ€™s truncated at 3 decimal places. So you can ignore them in this case and have them recorded in the Results window instead.

Iâ€™m looking at your results and see no 1 or NULL values - could you give an example where this happens please because it may be a bug.

2 Likes

Hello Michael,

Sorry, I only looked at the log window, thatâ€™s why I tought there was only nul values (but there isnâ€™t if you look attitude the results windowâ€¦)â€¦ I figured it out before but I could not delete the postâ€¦