Persist logged columns when we train in log space (#178)

* Add condo change;

* Edit comment

Author: wagnerlmichael

pipeline/01-train.R

@@ -440,12 +440,23 @@ walk2(
         )$.pred)
       )
 
+    # Preserve the log-scale outcome and prediction alongside their dollar
+    # equivalents. NA when the transform is off, since no log-space model
+    # output exists in that case
     if (log_transform_enable) {
       preds <- preds %>%
         mutate(
+          pred_card_initial_fmv_log = pred_card_initial_fmv,
+          meta_sale_price_log = meta_sale_price,
           pred_card_initial_fmv = exp(pred_card_initial_fmv),
           meta_sale_price = meta_sale_price_original
         )
+    } else {
+      preds <- preds %>%
+        mutate(
+          pred_card_initial_fmv_log = NA_real_,
+          meta_sale_price_log = NA_real_
+        )
     }
 
     preds %>%
@@ -456,8 +467,10 @@ walk2(
           "prior_far_tot" = params$ratio_study$far_column,
           "prior_near_tot" = params$ratio_study$near_column
         )),
-        pred_card_initial_fmv, pred_card_initial_fmv_lin,
-        meta_sale_price, meta_sale_date, meta_sale_document_num,
+        pred_card_initial_fmv, pred_card_initial_fmv_log,
+        pred_card_initial_fmv_lin,
+        meta_sale_price, meta_sale_price_log,
+        meta_sale_date, meta_sale_document_num,
         meta_modeling_group
       ) %>%
       # Prior year values are AV, not FMV. Multiply by 10 to

pipeline/02-assess.R

@@ -64,10 +64,17 @@ assessment_data_pred <- assessment_data_pred %>%
     )
   )
 
-# Exponentiate predictions back to raw dollar scale
+# Exponentiate predictions back to raw dollar scale, preserving
+# original log scale
 if (log_transform_enable) {
   assessment_data_pred <- assessment_data_pred %>%
-    mutate(pred_card_initial_fmv = exp(pred_card_initial_fmv))
+    mutate(
+      pred_card_initial_fmv_log = pred_card_initial_fmv,
+      pred_card_initial_fmv = exp(pred_card_initial_fmv)
+    )
+} else {
+  assessment_data_pred <- assessment_data_pred %>%
+    mutate(pred_card_initial_fmv_log = NA_real_)
 }
 
 
@@ -166,6 +173,7 @@ assessment_data_merged %>%
   select(
     meta_year, meta_pin, meta_class, meta_card_num, meta_lline_num,
     meta_modeling_group, ends_with("_num_sale"), pred_card_initial_fmv,
+    pred_card_initial_fmv_log,
     all_of(params$model$predictor$all), township_code
   ) %>%
   ccao::vars_recode(