Absolute value diff is incorrect

[rubypollev]

Absolute value diff is t1 - t2 when it should be |t1 - t2|. The absolute value function is not being applied.

superset/superset/viz.py

Line 1434 in 4e3d4f6

diff = df - df2

[zhaoyongjie]

@rubypollev The absolute function is not necessarily applied to diff results. cc: @junlincc

diff In the tableau

[rubypollev]

Tableau's implementation makes sense. This is a "difference." It can be negative.

Superset's implementation claims this same function is an "absolute difference," though, which it's not:

An absolute difference is non-negative by definition.

[zhaoyongjie]

Hi @rubypollev, thanks for your Issue, I will fix it asap.