A dataset containing chemical composition measurements from 25 tobacco leaf samples. This dataset is commonly used for demonstrating multivariate regression analysis and exploring relationships between chemical components and burn rate.
data(tobacco)A data frame with 25 rows and 9 variables:
Numeric. Rate of cigarette burn in inches per 1000 seconds.
Numeric. Percentage of sugar content in the leaf.
Numeric. Percentage of nicotine content.
Numeric. Percentage of nitrogen content.
Numeric. Percentage of chlorine content.
Numeric. Percentage of potassium content.
Numeric. Percentage of phosphorus content.
Numeric. Percentage of calcium content.
Numeric. Percentage of magnesium content.
Anderson, R. L. and Bancroft, T. A. (1952), Statistical Theory in Research, McGraw-Hill Book Company, Inc., New York, NY.
This dataset is particularly useful for:
Demonstrating multivariate regression analysis
Studying relationships between chemical composition and burn rate
Analyzing correlations between different chemical components
Teaching statistical methods in agricultural research
# Load the dataset
data(tobacco)
# View the first few rows
head(tobacco)
#> cigarette sugar nicotine nitrogen chlorine potassium phosphorus calcium
#> 1 1.55 20.05 1.38 2.02 2.90 2.17 0.51 3.47
#> 2 1.63 12.58 2.64 2.62 2.78 1.72 0.50 4.57
#> 3 1.66 18.56 1.56 2.08 2.68 2.40 0.43 3.52
#> 4 1.52 18.56 2.22 2.20 3.17 2.06 0.52 3.69
#> 5 1.70 14.02 2.85 2.38 2.52 2.18 0.42 4.01
#> 6 1.68 15.64 1.24 2.03 2.56 2.57 0.44 2.79
#> magnesium
#> 1 0.91
#> 2 1.25
#> 3 0.82
#> 4 0.97
#> 5 1.12
#> 6 0.82
# Summary statistics
summary(tobacco)
#> cigarette sugar nicotine nitrogen
#> Min. :1.400 Min. :12.58 Min. :1.240 Min. :1.720
#> 1st Qu.:1.550 1st Qu.:14.79 1st Qu.:1.870 1st Qu.:1.980
#> Median :1.680 Median :17.31 Median :2.160 Median :2.080
#> Mean :1.688 Mean :16.62 Mean :2.161 Mean :2.157
#> 3rd Qu.:1.780 3rd Qu.:18.55 3rd Qu.:2.430 3rd Qu.:2.210
#> Max. :2.090 Max. :20.05 Max. :3.280 Max. :2.870
#> chlorine potassium phosphorus calcium magnesium
#> Min. :0.740 Min. :1.64 Min. :0.42 Min. :2.790 Min. :0.780
#> 1st Qu.:2.150 1st Qu.:2.15 1st Qu.:0.48 1st Qu.:3.310 1st Qu.:0.860
#> Median :2.670 Median :2.22 Median :0.50 Median :3.560 Median :0.950
#> Mean :2.481 Mean :2.24 Mean :0.49 Mean :3.592 Mean :0.964
#> 3rd Qu.:2.840 3rd Qu.:2.40 3rd Qu.:0.51 3rd Qu.:3.720 3rd Qu.:1.040
#> Max. :3.300 Max. :2.64 Max. :0.56 Max. :4.570 Max. :1.250
# Correlation analysis
cor(tobacco)
#> cigarette sugar nicotine nitrogen chlorine
#> cigarette 1.0000000 -0.3198626 0.21555016 0.226000207 -0.62343918
#> sugar -0.3198626 1.0000000 -0.70199284 -0.705059364 0.42982387
#> nicotine 0.2155502 -0.7019928 1.00000000 0.768231725 -0.27053741
#> nitrogen 0.2260002 -0.7050594 0.76823172 1.000000000 -0.08936414
#> chlorine -0.6234392 0.4298239 -0.27053741 -0.089364140 1.00000000
#> potassium 0.4867307 0.1898693 -0.29428914 -0.007344682 -0.09292574
#> phosphorus -0.3204492 0.2438261 -0.04534413 -0.112258368 0.07383127
#> calcium -0.1212625 -0.4819467 0.68654613 0.627170771 0.13825072
#> magnesium -0.3134037 -0.5252157 0.73418610 0.604036129 0.11833719
#> potassium phosphorus calcium magnesium
#> cigarette 0.486730708 -0.32044919 -0.1212625 -0.3134037
#> sugar 0.189869253 0.24382615 -0.4819467 -0.5252157
#> nicotine -0.294289140 -0.04534413 0.6865461 0.7341861
#> nitrogen -0.007344682 -0.11225837 0.6271708 0.6040361
#> chlorine -0.092925739 0.07383127 0.1382507 0.1183372
#> potassium 1.000000000 -0.20542933 -0.5882255 -0.6108099
#> phosphorus -0.205429334 1.00000000 0.0138711 0.1549619
#> calcium -0.588225495 0.01387110 1.0000000 0.7638009
#> magnesium -0.610809895 0.15496189 0.7638009 1.0000000