Add the possibility to specify the min/max range of the color bar

[Anastasia Baryshnikova]

It sounds like a trivial thing but ends up being quite annoying. Especially because in most cases, the automatically determined color scale is not symmetric around 0 (e.g., goes from -0.8 to 0.4), therefore black does not automatically correspond to 0, and even if you sent the 2 extreme handles at symmetrical positions (e.g., -0.2 and 0.2), the colorbar looks asymmetric because the length of the right arm is different from the length of the left one.

[Anastasia Baryshnikova]

Also, the min/max of the colorscale should be able to go beyond the limits of the data. That will allow you to make your matrix extremely dark (by setting the 2 handles far beyond the limits of the data).

[Christopher Keil]

Starting work on this for alpha02.

[Anastasia Baryshnikova]

Use case: - You load a new matrix where, let's say, the values go from -1 to 0.5. You open the color settings and, first thing, you set the range of values on the color bar (min/max) from -0.5 to 0.5. This automatically puts the middle handle (black) to the middle (0 in this case), and the other two handles at -0.5 and 0.5. Every value lower than -0.5 gets the same color as -0.5.

Acceptance criteria: - Min/max can go outside the data range. - The values entered should be validated, i.e. min value has to be < max value. Otherwise, the user gets an alert and is invited to correct the error.

[Robert Leach]

I added some thoughts/notes to issue #136 along with some sample images I created that might be useful for this issue as well.

[Robert Leach]

Merged to master.

[Robert Leach]

Removing milestone: Color settings (automated comment)