galaxy: Galaxy Data

In ElemStatLearn: Data Sets, Functions and Examples from the Book: "The Elements of Statistical Learning, Data Mining, Inference, and Prediction" by Trevor Hastie, Robert Tibshirani and Jerome Friedman

Description

Radial Velocity of Galaxy NGC7531

Usage

data(galaxy)

Format

A data frame with 323 observations on the following 5 variables.

east.west

the east-west coordinate. The origin, (0,0), is near the center of the galaxy, east is negative, west is positive.

north.south

the north-south coordinate. The origin, (0,0), is near the center of the galaxy, south is negative, north is positive.

angle

degrees of counter-clockwise rotation from the horizon- tal of the slot within which the observation lies.

radial.position

signed distance from origin; negative if east-west coordinate is negative.

velocity

radial velocity measured in km/sec.

Details

The galaxy data frame records the radial velocity of a spiral galaxy measured at 323 points in the area of sky which it covers. All the measurements lie within seven slots crossing at the origin. The positions of the meas- urements given by four variables (columns).

Source

Buta, R. (1987) The Structure and Dynamics of Ringed Galaxies, III: Surface Photometry and Kinematics of the Ringed Nonbarred Spiral NGC7531. The Astrophysical J. Supplement Ser. Vol. 64, pp. 1–37.

John M. Chambers and Trevor J. Hastie, (eds.) Statistical Models in S, Wadsworth and Brooks, Pacific Grove, CA 1992, pg. 352.

Examples

str(galaxy) 
summary(galaxy)

Example output

'data.frame':	323 obs. of  5 variables:
 $ east.west      : num  8.46 7.96 7.47 6.97 6.47 ...
 $ north.south    : num  -38.2 -35.9 -33.7 -31.4 -29.2 ...
 $ angle          : num  102 102 102 102 102 ...
 $ radial.position: num  39.1 36.8 34.5 32.2 29.9 ...
 $ velocity       : int  1769 1749 1749 1758 1750 1745 1750 1753 1734 1710 ...
   east.west          north.south          angle        radial.position   
 Min.   :-29.66693   Min.   :-49.108   Min.   : 12.50   Min.   :-52.4000  
 1st Qu.: -7.91688   1st Qu.:-13.554   1st Qu.: 63.50   1st Qu.:-21.3500  
 Median : -0.06493   Median :  0.671   Median : 92.50   Median : -0.8000  
 Mean   : -0.33237   Mean   :  1.521   Mean   : 80.89   Mean   : -0.8427  
 3rd Qu.:  6.95053   3rd Qu.: 18.014   3rd Qu.:102.50   3rd Qu.: 19.6500  
 Max.   : 29.48414   Max.   : 49.889   Max.   :133.00   Max.   : 55.7000  
    velocity   
 Min.   :1409  
 1st Qu.:1523  
 Median :1586  
 Mean   :1594  
 3rd Qu.:1669  
 Max.   :1775  

ElemStatLearn documentation built on Aug. 12, 2019, 9:04 a.m.