title: I'm using stat_regline_equation with ggscatter. Is there a way to specify the significant digits of coefficients?
body: <p>I've found using <code>stat_regline_equation</code> (with <code>ggscatter</code>) to be really useful for quickly adding regression equations to plots, especially when I having multiple regressions on multiple facets. However, it seems to be stuck on 2 significant figures for terms. I know it is possible to extract coefficients from an <code>lm</code> and then display them with annotate. But with multiple facets that seems really daunting and finicky. Is there possibly a feature in the works (or already here, that I don't know about) to do this with <code>stat_regline_eq</code>? I have hope because you can specify digits with <code>stat_cor</code> for things like r-square and p-values! Any advice or help would be appreciated. Reproducible example below:</p>
  <pre><code>library(tidyverse)
  library(ggpubr)
  
  ggscatter(diamonds, x=&quot;carat&quot;, y=&quot;table&quot;, add=&quot;reg.line&quot;) +
    facet_wrap(~color) +
    stat_regline_equation(label.y=90)
  
  summary(lm(table ~ carat, data=filter(diamonds, color==&quot;D&quot;)))
  </code></pre>
  <p><a href="https://i.stack.imgur.com/Rj2Ru.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Rj2Ru.png" alt="output of ggscatter above" /></a></p>
  <pre><code>Coefficients:
              Estimate Std. Error t value Pr(&gt;|t|)    
  (Intercept) 56.46453    0.05438  1038.3   &lt;2e-16 ***
  carat        1.42911    0.07255    19.7   &lt;2e-16 ***
  </code></pre>
  <p>As you can see, the intercept shown in <code>ggscatter</code> for D is off by 0.5.</p>