#NEWLINE# @ pytest . mark . skipif ( ( 'DISPLAY' not in os . environ ) , reason = 'requires display' ) #NEWLINE# def test_exponential_data_sets_fit( ) : #NEWLINE# #INDENT# N = 20000 #NEWLINE# ( T , C ) = exponential_survival_data ( T , 0.2 , scale = 10 ) #NEWLINE# naf = NelsonAalenFitter ( ) #NEWLINE# naf . fit ( T , C ) . plot ( ) #NEWLINE# plt . title ( 'Should be a linear with slope = 0.1' )