Apply gradient effect to forgetting curve

[OuOu2021]

Preview:

a card with desired retention set to 0.95:

the same card, but with retention set to 0.70

Descriptions:

1. The reason for using tomato color instead of red is to reduce the obvious and confusing purple color between red and steel blue.
2. The center of steel blue color stands for the desired retention of the card.

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2024.12.5 update:

1. Add a reference line for desired retention.
2. Add y axis title.
3. Display the desired retention in the tooltip when the mouse is near the reference line.
   
4. I18n: make vertical axis title translatable & improve style
   

[chrislongros]

It looks beautiful

[dae]

I agree it looks good, but I think the colors need to use a range of 0-100, instead of the range that is displayed on the graph. 74 shouldn't be red. :-)

[OuOu2021]

I agree it looks good, but I think the colors need to use a range of 0-100, instead of the range that is displayed on the graph. 74 shouldn't be red. :-)

I modified the range as you suggested. Thank you very much.

[Expertium]

I guess I'm the minority - I don't like the color gradient here. But if everyone else is ok with it, may I at least offer a suggestion? Make desired retention a horizontal line.

[YukiNagat0]

I personally like the color gradient.

I guess I'm the minority - I don't like the color gradient here. But if everyone else is ok with it, may I at least offer a suggestion? Make desired retention a horizontal line.

The idea about the horizontal line for the desired retention seems very nice! Something like a dashed line (maybe with the same steelblue color) will be great!

[Expertium]

Also, add "Probability of recall" to the Y axis, please

[dae]

I ran into one issue: when changing the graph duration, multiple desired retention lines end up getting rendered:

Once that and the CONTRIBUTORS conflict is fixed, happy to merge. Thank you for your contribution!

[Expertium]

Maybe add "Desired retention" above the horizontal line to make it more obvious that it represents, well, desired retention?

[OuOu2021]

Maybe add "Desired retention" above the horizontal line to make it more obvious that it represents, well, desired retention?

I think the desired retention is clear enough in the tooltip so there is no need to add additional text into the chart, which may affect readability.

[dae]

Thank you!

[OuOu2021]

Thank you!

I'm glad I could contribute to a project that I use every day. Thank you for your guidance and support!

[sommerluk]

The string “Probability of Recall” is now showing up in the translation system. I wonder what is the exact meaning. I guess it is the same as “Retrievability”, which is used also in various other contexts in Anki, and also in the very same card statistics dialog, above in the list of data. If so, may I suggest renaming it to “Retrievability” for greater consistency?