how to update the list of global macro within foreach loop?

[Dominique Bourget]

Hello,
I am trying to run the code below, and my ultimate goal is to draw the scatter plot of the macros AUC vs. Alpha.
The AUC seem to be okay, but when I do ' list Alpha ' after running my code, the every value stored under the macro Alpha is 5, where as I want Alpha to be the list of same values used for `a1' (foreach a1 of numlist 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.5 5.0)

How can I resolve this issue? I am new to Stata so I have lots of questions.

Thank you,

STATA Code:

gen Alpha = .
gen AUC = .
local i = 1

foreach a1 of numlist 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.5 5.0 {

python: a = float(Macro.getLocal("a1"))

// predict using the best value for alpha
python: mnb = MultinomialNB(alpha = a, class_prior = None, fit_prior = True)

// calculate probability of each class on the test set
// '[:, 1]' at the end extracts the probability for each pharmacy to be under compliance
python: Y_mnb_score = mnb.fit(X_train, np.ravel(Y_train)).predict_proba(X_test)[:, 1]

// make test_compliance python variable
python: test_compliance = Y_test['compliance']

// transfer the python variables Y_mnb_score and test_compliance as global STATA variables
python: Data.setObsTotal(len(Y_mnb_score))
python: Data.addVarFloat('mnbScore')
python: Data.store(var = 'mnbScore', obs = None, val = Y_mnb_score)

python: Data.setObsTotal(len(test_compliance))
python: Data.addVarFloat('testCompliance')
python: Data.store(var = 'testCompliance', obs = None, val = test_compliance)


roctab testCompliance mnbScore
replace AUC = r(area) in `i'
replace Alpha = `a1' // this line is causing a problem

drop testCompliance mnbScore
local i = `++i'

}

scatter AUC Alpha xline(bestAlpha, lcolor(blue)) //ultimate goal

[William Lisowski]

replace AUC = r(area) in `i'

worked for your AUC variable, because each time it is run, it replaces the value of AUC only in one observation. That suggests that the very similar command

replace Alpha = `a1'

is not working because each time it is run, it replaces the value of Alpha in every observation. Try

replace Alpha = `a1' in `i'

[Dominique Bourget]

Thank you!