[R]単回帰分析

# 2変量の散布図
png('test1-0.png')
plot(cars)
dev.off()

# 単回帰分析（simple linear regression analysis）を行う
# lm: linear model
result <- lm(dist ~ speed, data=cars)
summary(result)

# 結果の直線を描画する
# abline(a, b): 切片a, 傾きb（y=a+bx）の直線を描く
# abline(result): resultにlm()の結果が入っている場合は回帰直線を描く
png('test1-1.png')
plot(cars)
abline(result, col="red")
dev.off()

実行結果

$ Rscript test1.R
null device
  1

Call:
lm(formula = dist ~ speed, data = cars)

Residuals:
  Min 1Q Median 3Q Max
-29.069 -9.525 -2.272 9.215 43.201

Coefficients:
  Estimate Std. Error t value Pr(>|t|)
(Intercept) -17.5791 6.7584 -2.601 0.0123 *
speed 3.9324 0.4155 9.464 1.49e-12 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 15.38 on 48 degrees of freedom
Multiple R-squared: 0.6511, Adjusted R-squared: 0.6438
F-statistic: 89.57 on 1 and 48 DF, p-value: 1.49e-12

null device
  1

出力結果
test1-0.png

test1-1.png