Téléverser les fichiers vers "/"

script.R

@@ -0,0 +1,49 @@
+var1 = function(x) {
+  return(mean(x**2)-mean(x)**2)
+}
+
+var2 = function(x,n) {
+  return(weighted.mean(x**2,n)-weighted.mean(x,n)**2)
+}
+
+sd1 = function(x) {
+  return(sqrt(var1(x)))
+}
+
+sd2 = function(x,n) {
+  return(sqrt(var2(x,n)))
+}
+
+covariance = function(x,y){
+  return(sum((x-mean(x))*(y-mean(y)))/length(x))
+}
+
+
+# correlation = function(x, y) {
+#   return(covariance(x,y)/(sd1(x) * sd1(y)))
+# }
+
+droite_yx = function(x, y) {
+  m = covariance(x,y) / var1(x)
+  p = mean(y) - m*mean(x)
+  return (c(m, p))
+}
+
+droite_xy = function(x, y) {
+  m = covariance(x, y) / var1(y)
+  p = mean(x) - m * mean(y)
+  return (c(m, p))
+}
+
+reg_yx <- droite_yx(x, y)
+reg_xy <- droite_xy(x, y)
+
+plot(x, y, 
+     main = "Régression Vitesse vs Distance de freinage",
+     xlab = "Vitesse (km/h)", 
+     ylab = "Distance de freinage (m)",
+     pch = 19, col = "blue", cex = 1.2)
+
+abline(a = reg_yx[2], b = reg_yx[1], col = "red", lwd = 1)
+
+abline(a = -reg_xy[2]/reg_xy[1], b = 1/reg_xy[1], col = "purple", lwd = 1)