I'm getting a weird result for DimensionLineDirection of an ordinate dimension.

For the basic dimension, the dimension line direction tells me the direction (in model coordinates?) of the dimension.

If I look at the model, this dimension is aligned with the Z-axis. This agrees with my understanding.

However, for the ordinate dimension, I get the following.

Basic Dimension:

[0,0,1]

Ordinate Dimension:

[1,0,0]

Actual direction in model coordinates:

[0,0,1]

My first guess was that the ordinate dimension's DimensionLineDirection is using the (Visible) extension line rather than the (Invisible) vector along which the dimension is measuring. However, if this were the case, it wouldn't be reported in the x-direction. If it was in drawing-coordinates, that line would be along the Y axis, if it were in model coordinates, that line would be along the Y axis still.

Does anyone have a guess?

Thanks,

John Alexander