Fix solution

inst/shinys/reg_simple_arrows/app.R

@@ -1,110 +1,112 @@
-library(dplyr)
-library(shiny)
-
-
-set.seed(19)
-
-# Generate Random Data
-x <- rnorm(n = 20, mean = 2, sd = 4)
-b_true <- -0.5
-a_true <- 1.5
-y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
-
-ui <- fluidPage(
-  br(),
-  br(),
-  sidebarPanel(sliderInput("i_simple", "Intercept", min = -4,
-                           max = 4, step = .05, value = .5),
-               sliderInput("s_simple", "Slope", min = -2,
-                           max = 2, step = .05, value = 0.1),
-               br(),
-               br(),
-
-               textOutput("userguess_simple")),
-
-  mainPanel(
-    plotOutput("regPlot_simple"),
-    textOutput("MSE")))
-
-
-server <- function(input,output){
-  output$userguess_simple <- renderText({
-
-    a <- input$i_simple
-    b <- input$s_simple
-    paste0("Your guess:\n y = ", a, " + ", b, "x")
-
-  })
-
-  output$regPlot_simple <- renderPlot({
-
-    # set.seed(19)
-    #
-    # # Generate Random Data
-    # x <- rnorm(n = 20, mean = 2, sd = 4)
-    #
-    # b_true <- -0.5
-    # a_true <- 1.5
-    # y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
-    # # True DGP: y = 1.5 -2 * x + u
-
-    # get data from disk
-    # load(file = system.file(package = "ScPoEconometrics","datasets","simple_arrows.RData"))
-
-    # a = intercept, b = slope (user input)
-    a <- input$i_simple
-    b <- input$s_simple
-
-
-    # plot
-    expr <- function(x) a + b*x
-    errors <- (a + b*x) - y
-
-    plot(x, y, type = "p", pch = 21, col = "blue", bg = "royalblue", asp=1,
-         # xlim = c(min(c(x))-1, max(c(x))+1),
-         # ylim = c(min(c(y))-1, max(c(y))+1),
-         main = "Find the Best Line! (Arrows turn Green!)", frame.plot = FALSE,
-         cex = 1.2)
-
-    if ((a == a_true) && (b == b_true)){
-      curve(expr = expr, from = min(x)-10, to = max(x)+10, add = TRUE, col = "black")
-      arrows(x, expr(x),
-             x, y,
-             col = 'green', lwd = 1, lty = 1, length = 0.1, angle = 20)
-    } else {
-      curve(expr =expr , from = min(x)-10, to = max(x)+10, add = TRUE, col = "black")
-      arrows(x, expr(x),
-             x, y,
-             col = 'red', lwd = 1, lty = 1, length = 0.1, angle = 20)
-    }
-    })
-
-    output$MSE <- renderText({
-      # set.seed(19)
-      # # Generate Random Data
-      # x <- rnorm(n = 20, mean = 2, sd = 4)
-      # b_true <- -0.5
-      # a_true <- 1.5
-      # y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
-      # # True DGP: y = -2 + 1.5 * x + u
-
-      # get data from disk
-      # load(file = system.file(package = "ScPoEconometrics","datasets","simple_arrows.RData"))
-
-
-      # a = intercept, b = slope (user input)
-      a <- input$i_simple
-      b <- input$s_simple
-
-
-      # plot
-      expr <- function(x) a + b*x
-      errors <- (a + b*x) - y
-
-      paste0("Total Sum of Errors = ", round(sum(errors),2)," || Total Sum of absolute Errors = ", round(sum(abs(errors)),2))
-
-    })
-}
-
-
-shinyApp(ui = ui, server = server)
+library(dplyr)
+library(shiny)
+
+
+set.seed(8)
+
+# Generate Random Data
+x <- rnorm(n = 20, mean = 2, sd = 4)
+b_true <- -0.5
+a_true <- 1.5
+y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
+a_solution <- round(2 * summary(lm(y ~ x))$coefficients[1, 1], 1) / 2
+b_solution <- round(2 * summary(lm(y ~ x))$coefficients[2, 1], 1) / 2
+
+ui <- fluidPage(
+  br(),
+  br(),
+  sidebarPanel(sliderInput("i_simple", "Intercept", min = -4,
+                           max = 4, step = .05, value = .5),
+               sliderInput("s_simple", "Slope", min = -2,
+                           max = 2, step = .05, value = 0.1),
+               br(),
+               br(),
+
+               textOutput("userguess_simple")),
+
+  mainPanel(
+    plotOutput("regPlot_simple"),
+    textOutput("MSE")))
+
+
+server <- function(input,output){
+  output$userguess_simple <- renderText({
+
+    a <- input$i_simple
+    b <- input$s_simple
+    paste0("Your guess:\n y = ", a, " + ", b, "x")
+
+  })
+
+  output$regPlot_simple <- renderPlot({
+
+    # set.seed(19)
+    #
+    # # Generate Random Data
+    # x <- rnorm(n = 20, mean = 2, sd = 4)
+    #
+    # b_true <- -0.5
+    # a_true <- 1.5
+    # y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
+    # # True DGP: y = 1.5 -2 * x + u
+
+    # get data from disk
+    # load(file = system.file(package = "ScPoEconometrics","datasets","simple_arrows.RData"))
+
+    # a = intercept, b = slope (user input)
+    a <- input$i_simple
+    b <- input$s_simple
+
+
+    # plot
+    expr <- function(x) a + b*x
+    errors <- (a + b*x) - y
+
+    plot(x, y, type = "p", pch = 21, col = "blue", bg = "royalblue", asp=1,
+         # xlim = c(min(c(x))-1, max(c(x))+1),
+         # ylim = c(min(c(y))-1, max(c(y))+1),
+         main = "Find the Best Line! (Arrows turn Green!)", frame.plot = FALSE,
+         cex = 1.2)
+
+    if ((a == a_solution) && (b == b_solution)){
+      curve(expr = expr, from = min(x)-10, to = max(x)+10, add = TRUE, col = "black")
+      arrows(x, expr(x),
+             x, y,
+             col = 'green', lwd = 1, lty = 1, length = 0.1, angle = 20)
+    } else {
+      curve(expr =expr , from = min(x)-10, to = max(x)+10, add = TRUE, col = "black")
+      arrows(x, expr(x),
+             x, y,
+             col = 'red', lwd = 1, lty = 1, length = 0.1, angle = 20)
+    }
+  })
+
+  output$MSE <- renderText({
+    # set.seed(19)
+    # # Generate Random Data
+    # x <- rnorm(n = 20, mean = 2, sd = 4)
+    # b_true <- -0.5
+    # a_true <- 1.5
+    # y <- a_true + b_true*x + rnorm(n = 20, mean = 0, sd = 2)
+    # # True DGP: y = -2 + 1.5 * x + u
+
+    # get data from disk
+    # load(file = system.file(package = "ScPoEconometrics","datasets","simple_arrows.RData"))
+
+
+    # a = intercept, b = slope (user input)
+    a <- input$i_simple
+    b <- input$s_simple
+
+
+    # plot
+    expr <- function(x) a + b*x
+    errors <- (a + b*x) - y
+
+    paste0("Total Sum of Errors = ", round(sum(errors),2)," || Total Sum of absolute Errors = ", round(sum(abs(errors)),2))
+
+  })
+}
+
+
+shinyApp(ui = ui, server = server)