I have a dataframe with values of B, P anda e, so i want to make a plot like this, but the problem is this black line that touch the y axis in 1.0 and x axis past 1.0 , it should be like a function where every point is given by the function B + P = e, but i don’t know how to make that condition to plot that line in abline. someone give me a light?
This is the code that i made, that already have the points, but I need them to be distinguished by color, like the example, and that diagonal line

    filter(!is.na(period),
           !is.na(air_force),
           !is.na(air_speed),
           !is.na(shear),
           !is.na(buoyancy),
           !is.na(V_TKE),
           !is.na(eps_u),
           buoyancy >= 0,
           level != 75) %>% 
    ggplot(aes(x = (buoyancy/eps_u), y = (-shear/eps_u)))+ 
    geom_point(alpha = 1, shape = 4)+
    geom_hline(yintercept = 0) +
    geom_vline(xintercept = 0)+
    coord_cartesian(ylim = c(-0.5, 1.5),
                    xlim = c(0, 3)) ```

[![B/e x P/e and a diagonal line where P + B = e](https://i.sstatic.net/D5iKcy4E.png)](https://i.sstatic.net/D5iKcy4E.png)