402 lines
9.0 KiB
Plaintext
402 lines
9.0 KiB
Plaintext
---
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title: "第10次课"
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editor: visual
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---
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```{r}
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require(tidymodels)
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taxi
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set.seed(123)
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taxi_split <- initial_split(taxi, prop = 0.8)
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taxi_train <- training(taxi_split)
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taxi_test <- testing(taxi_split)
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nrow(taxi_train)
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```
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```{r}
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tree_spec <-
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decision_tree(cost_complexity = 0.002) %>%
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set_mode("classification")
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tree_fit <-
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workflow(tip ~ ., tree_spec) %>%
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fit(data = taxi_train)
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taxi_test |>
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bind_cols(
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predict(tree_fit, new_data = taxi_test))
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```
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```{r}
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require(magrittr)
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# %>%: magrittr
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# |>: base
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taxi_folds <- vfold_cv(taxi_train, v = 5)
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tree_spec <-
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decision_tree(cost_complexity = 0.002) |>
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set_mode("classification")
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taxi_wflow <- workflow() |>
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add_formula(tip ~ .) |>
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add_model(tree_spec)
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taxi_res <- fit_resamples(taxi_wflow, taxi_folds)
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taxi_res
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taxi_metrics <- taxi_res |>
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collect_metrics()
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# Save the assessment set results
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ctrl_taxi <- control_resamples(save_pred = TRUE)
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taxi_res <- fit_resamples(taxi_wflow, taxi_folds, control = ctrl_taxi)
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taxi_res |>
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collect_predictions()
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taxi_metrics <- metric_set(accuracy, specificity, sensitivity)
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taxi_preds |>
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group_by(id) |>
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taxi_metrics(truth = tip, estimate = .pred_class)
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```
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## 数据
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```{r}
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require(tidyverse)
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sitedf <- readr::read_csv("https://www.epa.gov/sites/default/files/2014-01/nla2007_sampledlakeinformation_20091113.csv") |>
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select(SITE_ID,
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lon = LON_DD,
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lat = LAT_DD,
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name = LAKENAME,
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area = LAKEAREA,
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zmax = DEPTHMAX
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) |>
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group_by(SITE_ID) |>
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summarize(lon = mean(lon, na.rm = TRUE),
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lat = mean(lat, na.rm = TRUE),
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name = unique(name),
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area = mean(area, na.rm = TRUE),
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zmax = mean(zmax, na.rm = TRUE))
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visitdf <- readr::read_csv("https://www.epa.gov/sites/default/files/2013-09/nla2007_profile_20091008.csv") |>
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select(SITE_ID,
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date = DATE_PROFILE,
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year = YEAR,
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visit = VISIT_NO
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) |>
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distinct()
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waterchemdf <- readr::read_csv("https://www.epa.gov/sites/default/files/2013-09/nla2007_profile_20091008.csv") |>
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select(SITE_ID,
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date = DATE_PROFILE,
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depth = DEPTH,
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temp = TEMP_FIELD,
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do = DO_FIELD,
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ph = PH_FIELD,
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cond = COND_FIELD,
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)
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sddf <- readr::read_csv("https://www.epa.gov/sites/default/files/2014-10/nla2007_secchi_20091008.csv") |>
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select(SITE_ID,
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date = DATE_SECCHI,
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sd = SECMEAN,
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clear_to_bottom = CLEAR_TO_BOTTOM
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)
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trophicdf <- readr::read_csv("https://www.epa.gov/sites/default/files/2014-10/nla2007_trophic_conditionestimate_20091123.csv") |>
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select(SITE_ID,
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visit = VISIT_NO,
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tp = PTL,
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tn = NTL,
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chla = CHLA) |>
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left_join(visitdf, by = c("SITE_ID", "visit")) |>
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select(-year, -visit) |>
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group_by(SITE_ID, date) |>
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summarize(tp = mean(tp, na.rm = TRUE),
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tn = mean(tn, na.rm = TRUE),
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chla = mean(chla, na.rm = TRUE)
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)
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phytodf <- readr::read_csv("https://www.epa.gov/sites/default/files/2014-10/nla2007_phytoplankton_softalgaecount_20091023.csv") |>
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select(SITE_ID,
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date = DATEPHYT,
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depth = SAMPLE_DEPTH,
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phyta = DIVISION,
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genus = GENUS,
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species = SPECIES,
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tax = TAXANAME,
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abund = ABUND) |>
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mutate(phyta = gsub(" .*$", "", phyta)) |>
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filter(!is.na(genus)) |>
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group_by(SITE_ID, date, depth, phyta, genus) |>
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summarize(abund = sum(abund, na.rm = TRUE)) |>
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nest(phytodf = -c(SITE_ID, date))
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envdf <- waterchemdf |>
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filter(depth < 2) |>
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select(-depth) |>
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group_by(SITE_ID, date) |>
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summarise_all(~mean(., na.rm = TRUE)) |>
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ungroup() |>
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left_join(sddf, by = c("SITE_ID", "date")) |>
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left_join(trophicdf, by = c("SITE_ID", "date"))
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nla <- envdf |>
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left_join(phytodf) |>
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left_join(sitedf, by = "SITE_ID") |>
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filter(!purrr::map_lgl(phytodf, is.null)) |>
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mutate(cyanophyta = purrr::map(phytodf, ~ .x |>
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dplyr::filter(phyta == "Cyanophyta") |>
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summarize(cyanophyta = sum(abund, na.rm = TRUE))
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)) |>
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unnest(cyanophyta) |>
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select(-phyta) |>
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mutate(clear_to_bottom = ifelse(is.na(clear_to_bottom), TRUE, FALSE))
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# library(rmdify)
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# library(dwfun)
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# dwfun::init()
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```
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```{r}
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skimr::skim(nla)
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```
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```{r}
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nla |>
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filter(tp > 1) |>
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ggplot(aes(tn, tp)) +
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geom_point() +
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geom_smooth(method = "lm") +
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scale_x_log10(breaks = scales::trans_breaks("log10", function(x) 10^x),
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labels = scales::trans_format("log10", scales::math_format(10^.x))) +
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scale_y_log10(breaks = scales::trans_breaks("log10", function(x) 10^x),
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labels = scales::trans_format("log10", scales::math_format(10^.x)))
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m1 <- lm(log10(tp) ~ log10(tn), data = nla)
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summary(m1)
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```
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```{r}
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nla |>
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filter(tp > 1) |>
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ggplot(aes(tp, cyanophyta)) +
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geom_point() +
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geom_smooth(method = "lm") +
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scale_x_log10(breaks = scales::trans_breaks("log10", function(x) 10^x),
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labels = scales::trans_format("log10", scales::math_format(10^.x))) +
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scale_y_log10(breaks = scales::trans_breaks("log10", function(x) 10^x),
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labels = scales::trans_format("log10", scales::math_format(10^.x)))
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m2 <- lm(log10(cyanophyta) ~ log10(tp), data = nla)
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summary(m2)
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m3 <- glm(log10(cyanophyta) ~ log10(tp), data = nla)
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summary(m3)
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require(mgcv)
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# 广义加性模型 General additive model
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m4 <- gam(log10(cyanophyta) ~ s(log10(tp)) + s(log10(tn)) + s(log10(chla)), data = nla)
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plot(m4)
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summary(m4)
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```
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```{r}
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nla_split <- initial_split(nla, prop = 0.7, strata = zmax)
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nla_train <- training(nla_split)
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nla_test <- testing(nla_split)
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```
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```{r}
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# xgboost, cyanophyta
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nla_formula <- as.formula("cyanophyta ~ temp + do + ph + cond + sd + tp + tn + chla + clear_to_bottom")
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# nla_formula <- as.formula("cyanophyta ~ temp + do + ph + cond + sd + tp + tn")
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nla_recipe <- recipes::recipe(nla_formula, data = nla_train) |>
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recipes::step_string2factor(all_nominal()) |>
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recipes::step_nzv(all_nominal()) |>
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recipes::step_log(chla, cyanophyta, tn, tp, base = 10) |>
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recipes::step_normalize(all_numeric_predictors()) |>
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prep()
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nla_recipe
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```
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```{r}
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nla_cv <- recipes::bake(
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nla_recipe,
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new_data = nla_train
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) |>
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rsample::vfold_cv(v = 10)
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nla_cv
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```
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```{r}
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xgboost_model <- parsnip::boost_tree(
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mode = "regression",
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trees = 1000,
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min_n = tune(),
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tree_depth = tune(),
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learn_rate = tune(),
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loss_reduction = tune()
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) |>
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set_engine("xgboost", objective = "reg:squarederror")
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xgboost_model
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```
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```{r}
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# grid specification
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xgboost_params <- dials::parameters(
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min_n(),
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tree_depth(),
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learn_rate(),
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loss_reduction()
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)
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xgboost_params
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```
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```{r}
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xgboost_grid <- dials::grid_max_entropy(
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xgboost_params,
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size = 60
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)
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knitr::kable(head(xgboost_grid))
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```
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```{r}
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xgboost_wf <- workflows::workflow() |>
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add_model(xgboost_model) |>
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add_formula(nla_formula)
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xgboost_wf
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```
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```{r}
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install.packages("xgboost")
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# hyperparameter tuning
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if (FALSE) {
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xgboost_tuned <- tune::tune_grid(
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object = xgboost_wf,
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resamples = nla_cv,
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grid = xgboost_grid,
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metrics = yardstick::metric_set(rmse, rsq, mae),
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control = tune::control_grid(verbose = TRUE)
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)
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saveRDS(xgboost_tuned, "./xgboost_tuned.RDS")
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}
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xgboost_tuned <- readRDS("./xgboost_tuned.RDS")
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```
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```{r}
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xgboost_tuned |>
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tune::show_best(metric = "rmse") |>
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knitr::kable()
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```
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```{r}
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xgboost_tuned |>
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collect_metrics()
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```
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```{r}
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xgboost_tuned |>
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autoplot()
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```
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```{r}
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xgboost_best_params <- xgboost_tuned |>
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tune::select_best("rmse")
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knitr::kable(xgboost_best_params)
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```
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```{r}
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xgboost_model_final <- xgboost_model |>
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finalize_model(xgboost_best_params)
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xgboost_model_final
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```
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```{r}
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(train_processed <- bake(nla_recipe, new_data = nla_train))
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```
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```{r}
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train_prediction <- xgboost_model_final |>
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# fit the model on all the training data
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fit(
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formula = nla_formula,
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data = train_processed
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) |>
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# predict the sale prices for the training data
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predict(new_data = train_processed) |>
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bind_cols(nla_train |>
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mutate(.obs = log10(cyanophyta)))
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xgboost_score_train <-
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train_prediction |>
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yardstick::metrics(.obs, .pred) |>
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mutate(.estimate = format(round(.estimate, 2), big.mark = ","))
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knitr::kable(xgboost_score_train)
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```
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```{r}
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train_prediction |>
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ggplot(aes(.pred, .obs)) +
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geom_point() +
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geom_smooth(method = "lm")
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```
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```{r}
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test_processed <- bake(nla_recipe, new_data = nla_test)
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test_prediction <- xgboost_model_final |>
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# fit the model on all the training data
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fit(
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formula = nla_formula,
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data = train_processed
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) |>
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# use the training model fit to predict the test data
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predict(new_data = test_processed) |>
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bind_cols(nla_test |>
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mutate(.obs = log10(cyanophyta)))
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# measure the accuracy of our model using `yardstick`
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xgboost_score <- test_prediction |>
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yardstick::metrics(.obs, .pred) |>
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mutate(.estimate = format(round(.estimate, 2), big.mark = ","))
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knitr::kable(xgboost_score)
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```
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```{r}
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cyanophyta_prediction_residual <- test_prediction |>
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arrange(.pred) %>%
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mutate(residual_pct = (.obs - .pred) / .pred) |>
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select(.pred, residual_pct)
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cyanophyta_prediction_residual |>
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ggplot(aes(x = .pred, y = residual_pct)) +
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geom_point() +
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xlab("Predicted Cyanophyta") +
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ylab("Residual (%)")
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```
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```{r}
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test_prediction |>
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ggplot(aes(.pred, .obs)) +
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geom_point() +
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geom_smooth(method = "lm", colour = "black")
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```
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