# # Written by: # -- # John L. Weatherwax 2009-04-21 # # email: wax@alum.mit.edu # # Please send comments and especially bug reports to the # above email address. # # EPage 505-508 # #----- source('wilcoxon_rank_sum_test.R') # Ex 15.10: EPage 613; Anwsers EPage 708 # x_data = c( 229, 286, 245, 299, 250 ) y_data = c( 213, 179, 163, 247, 225 ) out = wilcoxon_rank_sum_test( x_data, y_data ) print( out$w ) # Ex 15.11: EPage 613; Anwsers EPage 708 # DF = read.csv( "../../Data/CH15/ex15-11.txt", header=TRUE, quote="'" ) x_data = DF[ DF$Wood == 'Oak', ]$Time y_data = DF[ DF$Wood == 'Pine', ]$Time out = wilcoxon_rank_sum_test( x_data, y_data ) print( out$w ) # Ex 15.12: EPage 613; Anwsers EPage 708 # DF = read.csv( "../../Data/CH15/ex15-12.txt", header=TRUE, quote="'" ) x_data = DF[ DF$process == 'Original', ]$time y_data = DF[ DF$process == 'Modified', ]$time out = wilcoxon_rank_sum_test( x_data, y_data, Delta_0=1 ) print( out$w ) # Ex 15.13: EPage 613; Anwsers EPage 708 # DF = read.csv( "../../Data/CH15/ex15-13.txt", header=TRUE, quote="'" ) x_data = DF[ DF$'Vit.C.source' == 'Orange Juice', ]$Time y_data = DF[ DF$'Vit.C.source' == 'Ascorbic Acid', ]$Time out = wilcoxon_rank_sum_test( x_data, y_data ) print( out ) z = ( out$w - out$mu_w ) / out$sigma_w print( z ) print( 2*(1 - pnorm( abs(z) )) ) # Ex 15.14: EPage 613; Anwsers EPage 708 # DF = read.csv( "../../Data/CH15/ex15-13.txt", header=TRUE, quote="'" ) # mostly this data is the same ... x_data = DF[ DF$'Vit.C.source' == 'Orange Juice', ]$Time y_data = DF[ DF$'Vit.C.source' == 'Ascorbic Acid', ]$Time x_data[2] = 9.5 # adjust x_data and y_data x_data[3] = 9.5 y_data[7] = 9.5 y_data[8] = 10.0 y_data[9] = 11.5 out = wilcoxon_rank_sum_test( x_data, y_data ) print( out ) z = ( out$w - out$mu_w ) / out$sigma_w print( z ) print( 2*(1 - pnorm( abs(z) )) ) # Ex 15.15: EPage 613; Anwsers EPage 708 # DF = read.csv( "../../Data/CH15/ex15-15.txt", header=TRUE, quote="'" ) x_data = DF[ DF$'smoke' == 'Unexposed', ]$cotanine y_data = DF[ DF$'smoke' == 'Exposed', ]$cotanine out = wilcoxon_rank_sum_test( x_data, y_data, Delta_0=-25 ) print( out ) # Ex 15.16: EPage 613; Anwsers EPage 708; Exercise 79 Chapter 9 EPage 366 # DF = read.csv( "../../Data/CH09/ex9-81.txt", header=TRUE, quote="'" ) # not sure why this is problem 81 ... x_data = DF[ DF$'visibility' == 'Good', ]$time y_data = DF[ DF$'visibility' == 'Poor', ]$time out = wilcoxon_rank_sum_test( x_data, y_data ) print( out )