[figures] make py3 compatible

bootstrap/lecture/bootstrapsem.py

@@ -15,13 +15,13 @@ x = rng.randn(nsamples)
 
 # bootstrap the mean:
 mus = []
-for i in xrange(nresamples) :
+for i in range(nresamples) :
     mus.append(np.mean(x[rng.randint(0, nsamples, nsamples)]))
 hmus, _ = np.histogram(mus, bins, density=True)
 
 # many SRS:
 musrs = []
-for i in xrange(nresamples) :
+for i in range(nresamples) :
     musrs.append(np.mean(rng.randn(nsamples)))
 hmusrs, _ = np.histogram(musrs, bins, density=True)
 

bootstrap/lecture/permutecorrelation.py

@@ -19,7 +19,7 @@ rd = np.corrcoef(x, y)[0, 1]
 # permutation:
 nperm = 1000
 rs = []
-for i in xrange(nperm) :
+for i in np.arange(nperm) :
     xr=rng.permutation(x)
     yr=rng.permutation(y)
     rs.append( np.corrcoef(xr, yr)[0, 1] )