lm按分类变量(因子)进行分组

时间:2015-04-29 14:20:37

标签: r grouping regression linear-regression

我有下表,我很想获得每个行业的lm斜坡数据框。每个行业的年份都是1999年 - 2012年,我只是在新表中寻找每个行业的斜率。

> head(mmfpdatad)
  YEAR industry       index
1 1999    Farms -0.02352551
2 2000    Farms  0.04081992
3 2001    Farms  0.02435490
4 2002    Farms  0.01056180
5 2003    Farms  0.04876939
6 2004    Farms -0.01805118

1 个答案:

答案 0 :(得分:1)

使用mtcars作为示例数据,您可以尝试:

mtcars$slope <- ave(mtcars$mpg, as.factor(mtcars$gear), FUN = function(x) lm(x ~ seq_along(x))$coef[[2]])

给出了每档的坡度:

mtcars
                     mpg cyl  disp  hp drat    wt  qsec vs am gear carb      slope
Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4  0.6860140
Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4  0.6860140
Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1  0.6860140
Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1 -0.1864286
Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2 -0.1864286
Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1 -0.1864286
Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4 -0.1864286
Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2  0.6860140
Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2  0.6860140
Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4  0.6860140
Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4  0.6860140
Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3 -0.1864286
Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3 -0.1864286
Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3 -0.1864286
Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4 -0.1864286
Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4 -0.1864286
Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4 -0.1864286
Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1  0.6860140
Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2  0.6860140
Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1  0.6860140
Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1 -0.1864286
Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2 -0.1864286
AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2 -0.1864286
Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4 -0.1864286
Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2 -0.1864286
Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1  0.6860140
Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2 -3.2700000
Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2 -3.2700000
Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4 -3.2700000
Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6 -3.2700000
Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8 -3.2700000
Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2  0.6860140