updated simulations vignette

Author: jhelvy

NEWS.md

@@ -4,6 +4,7 @@
 ## Summary of larger updates:
 
 - Added support for auto creating interactions amongst variables
+- exported `getCoefTable()` function
 
 ## Summary of smaller updates:
 

README.Rmd

@@ -10,12 +10,12 @@ knitr::opts_chunk$set(
   warning    = FALSE,
   message    = FALSE,
   comment    = "#>",
-  fig.path   = "man/figures/",
+  fig.path   = "man/figs/",
   fig.retina = 3
 )
 ```
 
-# logitr <a href='https://jhelvy.github.io/logitr/'><img src='man/figures/logitr-hex.png' align="right" height="139" /></a>
+# logitr <a href='https://jhelvy.github.io/logitr/'><img src='man/figs/logitr-hex.png' align="right" height="139" /></a>
 
 <!-- badges: start -->
 [![Lifecycle:

README.md

@@ -1,7 +1,7 @@
 
 <!-- README.md is generated from README.Rmd. Please edit that file -->
 
-# logitr <a href='https://jhelvy.github.io/logitr/'><img src='man/figures/logitr-hex.png' align="right" height="139" /></a>
+# logitr <a href='https://jhelvy.github.io/logitr/'><img src='man/figs/logitr-hex.png' align="right" height="139" /></a>
 
 <!-- badges: start -->
 
@@ -88,16 +88,16 @@ citation("logitr")
 #> 
 #> To cite logitr in publications use:
 #> 
-#>   John Paul Helveston. logitr: Random utility logit models with
-#>   preference and willingness to pay space parameterizations (2020)
+#>   John Paul Helveston (2020). logitr: Random utility logit models with
+#>   preference and willingness to pay space parameterizations.
 #> 
 #> A BibTeX entry for LaTeX users is
 #> 
 #>   @Manual{,
 #>     title = {logitr: Random utility logit models with preference and willingness to pay space parameterizations},
 #>     author = {John Paul Helveston},
 #>     year = {2020},
-#>     note = {R package version 0.0.4},
+#>     note = {R package version 0.0.5},
 #>     url = {https://jhelvy.github.io/logitr/},
 #>   }
 ```

_pkgdown.yml

@@ -54,6 +54,7 @@ reference:
   contents:
   - summary.logitr
   - coef.logitr
+  - getCoefTable
   - statusCodes
 - title: "Computing and Comparing WTP"
   desc: "Functions for computing and comparing WTP from estimated models."

inst/example/simulations.R

@@ -49,16 +49,6 @@ sim_mxl_pref
 sim_mxl_wtp <- simulateShares(mxl_wtp, alts, priceName = 'price')
 sim_mxl_wtp
 
-# Plot simulation results from preference space MNL model:
-library(ggplot2)
-sim_mnl_pref$alt <- row.names(sim_mnl_pref)
-ggplot(sim_mnl_pref, aes(x = alt, y = share_mean)) +
-    geom_bar(stat = 'identity', width = 0.7, fill = "dodgerblue") +
-    geom_errorbar(aes(ymin = share_low, ymax = share_high), width = 0.2) +
-    scale_y_continuous(limits = c(0, 1)) +
-    labs(x = 'Alternative', y = 'Expected Share') +
-    theme_bw()
-
 # Save results
 saveRDS(sim_mnl_pref,
         here::here('inst', 'extdata', 'sim_mnl_pref.Rds'))
@@ -68,3 +58,19 @@ saveRDS(sim_mxl_pref,
         here::here('inst', 'extdata', 'sim_mxl_pref.Rds'))
 saveRDS(sim_mxl_wtp,
         here::here('inst', 'extdata', 'sim_mxl_wtp.Rds'))
+
+# Plot simulation results from each model:
+library(ggplot2)
+
+sims <- rbind(sim_mnl_pref, sim_mnl_wtp, sim_mxl_pref, sim_mxl_wtp)
+sims$model <- c(rep("mnl_pref", 4), rep("mnl_wtp", 4),
+                rep("mxl_pref", 4), rep("mxl_wtp", 4))
+sims$alt <- rep(row.names(alts), 4)
+
+ggplot(sims, aes(x = alt, y = share_mean, fill = model)) +
+    geom_bar(stat = 'identity', width = 0.7, position = "dodge") +
+    geom_errorbar(aes(ymin = share_low, ymax = share_high),
+                  width = 0.2, position = position_dodge(width = 0.7)) +
+    scale_y_continuous(limits = c(0, 1)) +
+    labs(x = 'Alternative', y = 'Expected Share') +
+    theme_bw()

inst/extdata/sim_mnl_pref.Rds

@@ -1,14 +1,6 @@
-# logitr 0.0.5
+# logitr 0.0.6
 
 ## Summary of larger updates:
 
-- Added support for creating interactions amongst variables
 
 ## Summary of smaller updates:
-
-- Added new documentation for prepping data:
-    - overall structure
-    - dummyCode() function
-    - handling interactions
-- All vignettes proof-read with lots of small changes to examples
-- Added a hex sticker

inst/extdata/sim_mnl_wtp.Rds

@@ -158,7 +158,7 @@ summary(mnl_wtp_weighted)
 
 # Compare results
 
-Here is a comparison of the coefficients between the weighted and unweighted models. All of the significant coefficients:
+Here is a comparison of the coefficients between the weighted and unweighted models. All of the significant coefficients have the same sign, but the magnitudes shift some based on the differential weighting of each individual choice in the weighted model:
 
 ```{r}
 coef_compare <- data.frame(
@@ -167,7 +167,7 @@ coef_compare <- data.frame(
 coef_compare
 ```
 
-Compare the log-likelihood between the weighted and unweighted models:
+Here is a comparison of the log-likelihood for the weighted and unweighted models:
 
 ```{r}
 logLik_compare <- c(

inst/extdata/sim_mxl_pref.Rds

@@ -13,6 +13,7 @@ knitr::opts_chunk$set(
   collapse = TRUE,
   warning = FALSE,
   message = FALSE,
+  fig.path   = "figs/",
   fig.retina = 3,
   comment = "#>"
 )
@@ -60,6 +61,10 @@ You can also use WTP space models to simulate shares, but you must provide the a
 ```{r, eval=FALSE}
 sim_mnl_wtp <- simulateShares(mnl_wtp, alts, priceName = 'price')
 ```
+```
+#> **Using results for model 1 of 10,
+#> the best model (largest log-likelihood) from the multistart**
+```
 ```{r}
 sim_mnl_wtp
 ```
@@ -83,3 +88,24 @@ sim_mxl_wtp <- simulateShares(mxl_wtp, alts, priceName = 'price')
 ```{r}
 sim_mxl_wtp
 ```
+
+Here is a bar plot of the results from each model:
+
+```{r, fig.width=6, fig.height=4}
+library(ggplot2)
+
+sims <- rbind(sim_mnl_pref, sim_mnl_wtp, sim_mxl_pref, sim_mxl_wtp)
+sims$model <- c(rep("mnl_pref", 4), rep("mnl_wtp", 4),
+                rep("mxl_pref", 4), rep("mxl_wtp", 4))
+sims$alt <- rep(row.names(alts), 4)
+
+ggplot(sims, aes(x = alt, y = share_mean, fill = model)) +
+    geom_bar(stat = 'identity', width = 0.7, position = "dodge") +
+    geom_errorbar(aes(ymin = share_low, ymax = share_high),
+                  width = 0.2, position = position_dodge(width = 0.7)) +
+    scale_y_continuous(limits = c(0, 1)) +
+    labs(x = 'Alternative', y = 'Expected Share') +
+    theme_bw()
+```
+
+# References