add citation

Author: joethorley

NEWS.md

@@ -1,5 +1,6 @@
 # ssdtools 0.0.3
 
+- added citation
 - Added ssdtools-manual vignette
 - Changed predict() and ssd_hc() nboot argument from 1001 to 1000
 - Added hc5_boron data object

README.Rmd

@@ -86,6 +86,8 @@ ssd_plot(boron_data, boron_pred, shape = "Group", color = "Group", label = "Spec
          xlab = "Concentration (mg/L)", ribbon = TRUE) + expand_limits(x = 3000)
 ```
 
+## Information
+
 The ssdtools manual is available at <https://bcgov.github.io/ssdtools/articles/ssdtools-manual.html>.
 
 A shiny webpage developed for non-R-users is available at <https://poissonconsulting.shinyapps.io/ssdtools/>.
@@ -96,6 +98,13 @@ The data included in `ssdtools` are sourced from the Canadian environmental qual
 
 To report bugs/issues/feature requests, please file an [issue](https://github.com/bcgov/ssdtools/issues/).
 
+## Citation
+
+```{r, comment = "", echo = FALSE}
+citation(package = "ssdtools")
+```
+
+
 ## How to Contribute
 
 If you would like to contribute to the package, please see our 

README.md

@@ -123,6 +123,8 @@ ssd_plot(boron_data, boron_pred, shape = "Group", color = "Group", label = "Spec
 
 ![](man/figures/README-unnamed-chunk-10-1.png)<!-- -->
 
+## Information
+
 The ssdtools manual is available at
 <https://bcgov.github.io/ssdtools/articles/ssdtools-manual.html>.
 
@@ -141,6 +143,30 @@ folder for more information.
 To report bugs/issues/feature requests, please file an
 [issue](https://github.com/bcgov/ssdtools/issues/).
 
+## Citation
+
+``` 
+
+To cite ssdtools in publications use:
+
+  Thorley et al., (2018). ssdtools An R package to fit Species
+  Sensitivity Distributions. Journal of Open Source Software,
+  3(31), 1082. https://doi.org/10.21105/joss.01082
+
+A BibTeX entry for LaTeX users is
+
+  @Article{,
+    title = {{ssdtools}: An R package to fit Species Sensitivity Distributions},
+    author = {Joe Thorley and Carl Schwarz},
+    journal = {Journal of Open Source Software},
+    year = {2018},
+    volume = {3},
+    number = {31},
+    pages = {1082},
+    doi = {10.21105/joss.01082},
+  }
+```
+
 ## How to Contribute
 
 If you would like to contribute to the package, please see our