MTB > # example 3.2.1 from Schmitt (1969) MTB > # --------------------------------- MTB > # Machine in a factory is producing metal parts. Most of MTB > # the time (90% by long records) it produces 95% good parts. MTB > # Sometimes it settles into a less productive mode and MTB > # only produces 70% good parts. If s = satisfactory and MTB > # u = unsatisfactory, then the first dozen parts produced one MTB > # morning are s,u,s,s,s,s,s,s,s,u,s,u. Should foreman stop MTB > # the machine? MTB > MTB > exec 'bayes_se' INPUT NUMBER OF MODELS: DATA> 2 INPUT NAMES OF MODELS (ONE NAME ON EACH LINE): DATA> working DATA> broken INPUT PRIOR PROBABILITIES OF MODELS: DATA> .9 .1 INPUT THE NUMBER OF POSSIBLE OUTCOMES: DATA> 2 INPUT THE NAME OF EACH OBSERVATION: (ONE OBSERVATION ON A LINE) DATA> s DATA> u INPUT LIKELIHOODS OF EACH MODEL: MODEL 1 DATA> .95 .05 MODEL 2 DATA> .7 .3 OBSERVATION NAMES: Row OBS OBS_NAME 1 OUT_1 s 2 OUT_2 u TABLE OF PROBABILITIES OF MODELS AND OUTCOMES: Row MODEL NAME PRIOR OUT_1 OUT_2 1 1 working 0.9 0.95 0.05 2 2 broken 0.1 0.70 0.30 MTB > exec 'bayes' INPUT NUMBER OF OBSERVATIONS: DATA> 12 INPUT OBSERVATIONS: (ONE OBSERVATION NAME ON A LINE:) DATA> s DATA> u DATA> s DATA> s DATA> s DATA> s DATA> s DATA> s DATA> s DATA> u DATA> s DATA> u OUTCOME s Row MODEL NAME PRIOR LIKE PRODUCT POST 1 1 working 0.9 0.95 0.855 0.924324 2 2 broken 0.1 0.70 0.070 0.075676 ... OUTCOME u Row MODEL NAME PRIOR LIKE PRODUCT POST 1 1 working 0.796107 0.05 0.0398054 0.394217 2 2 broken 0.203893 0.30 0.0611678 0.605783 MTB > name c1 'log_odds' MTB > let c1=logten('prob_m1'/'prob_m2') MTB > prin 'OBS_NO' 'OUTCOMES' 'PROB_M1' 'PROB_M2' 'log_odds' Row OBS_NO OUTCOMES PROB_M1 PROB_M2 log_odds 1 0 0.900000 0.100000 0.95424 2 1 s 0.924324 0.075676 1.08687 3 2 u 0.670588 0.329412 0.30872 4 3 s 0.734237 0.265763 0.44134 5 4 s 0.789449 0.210551 0.57397 6 5 s 0.835757 0.164243 0.70659 7 6 s 0.873512 0.126488 0.83922 8 7 s 0.903589 0.096411 0.97184 9 8 s 0.927111 0.072889 1.10447 10 9 s 0.945242 0.054758 1.23710 11 10 u 0.742071 0.257929 0.45894 12 11 s 0.796107 0.203893 0.59157 13 12 u 0.394217 0.605783 -0.18658