Set alpha values from dataframe

[NathanGuy14]

In ggplot2, the alpha values of each cell in a heatmap can be set individually, using the aes() function. Can the same be done in heatmaply?

[talgalili]

Hi NathanGuy14 This is not currently implemented, but it could probably be added. Could you help illustrate what would be the use case for this? (alpha is usually for overlayed elements, and in this case if you want to just change the color pallette you could do that directly)

[NathanGuy14]

Sure! What I'd like to do is set certain cells of my heatmap to be more transparent if the uncertainty in the measurement is higher. So I'd have one data frame of measurements and another data frame of variances or standard deviations, and set my alpha values based on the variances. This is mentioned here for ggplot. https://ggplot2.tidyverse.org/reference/scale_alpha.html Thanks for considering this! Nathanguy14

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On Sat, Apr 21, 2018, 1:26 AM Tal Galili ***@***.***> wrote: Hi NathanGuy14 This is not currently implemented, but it could probably be added. Could you help illustrate what would be the use case for this? (alpha is usually for overlayed elements, and in this case if you want to just change the color pallette you could do that directly) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#174 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AKCJMIMxrERbGjb1cvc8GLvFfnF5rhn7ks5tqsMRgaJpZM4TeQCn> .

[alanocallaghan]

I don't know if this is properly supported in plotly as of right now:

library(ggplot2)
library(plotly)

g <- ggplot(mtcars, aes(x=factor(cyl), y = factor(carb), fill = mpg, alpha = vs)) + geom_tile()
print(g)

print(ggplotly(g))