The usage of transformation in tutorial is not correct

[Jingnan-Jia]

In this 3D segmentation tutorial, two transformations are used:

                    rotate_range=(-0.05, 0.05),
                    scale_range=(-0.1, 0.1),

I think the two lines make the usage confusing. The two lines implicit the usage of rotate_range and scale_range should be

                    rotate_range=(min, max),
                    scale_range=(min, max),

It made me thought that the rotation_range for the 3 dimentions would be the same: a random value between (-0.05, 0.05) , and I also thought that the scale_range for the 3 dimentions would be the same: a random value between (-0.1, 0.1) .

However, it is not the truth. Actually, the rotation_range for the first dimention would be a random value between (0.05, -0.05) , the rotation_range for the second dimention would be another random value between (-0.05, 0.05) , and the rotation_range for the third dimention would be None. Because in the source code:

            self.rotate_params = [self.R.uniform(-f, f) for f in self.rotate_range if f is not None]

So the correct usage should be

                    rotate_range=(rotate_range_1, rotate_range_2, rotate_range_3),
                    scale_range=(scale_range_1, scale_range_2, scale_range_3),

And it is not necessary to set rotate_range_1 a negative value at all!

Therefore I advice to replace the original code from

                    rotate_range=(-0.05, 0.05),
                    scale_range=(-0.1, 0.1),

to

                    rotate_range=(0.05, 0.05, 0.5),
                    scale_range=(0.1, 0.1, 0.1),

so that we can tell the readers the correct usage of the rotate_range and scale_range.

[rijobro]

Hi, good spot that certainly looks like a typo to me! Would you be interested in creating a PR to address this issue?

Note that your suggested changes would change the output slightly, since previously the 3rd dimension would have been None. If you find the results to be degraded (which I doubt), then maybe switch to using rotate_range=(0.05, 0.05, None), etc.

[Jingnan-Jia]

I have already created a PR, please help to review it.