python 3.x - 'float' object is unsliceable -

i'm trying generate 2 classes of random 2d points, 1 having mean of [1,1] , other mean of [-1,-1]. have written function error can't figure out. googled didn't find anything. here's function :

def gen_arti_bis(nbex=10,centerx=1,centery=1,sigma=0.1,epsilon=0.02):     xpos=np.random.multivariate_normal([centerx,centery],np.diag([sigma,sigma]),nbex/2)     xneg=np.random.multivariate_normal([-centerx,-centery],np.diag([sigma,sigma]),nbex/2)     data=np.vstack((xpos,xneg))     y=np.hstack((np.ones(nbex/2),-np.ones(nbex/2)))     return data,y 

and here's error message when type gen_arti():

traceback (most recent call last):   file "<ipython-input-64-a173cf922dac>", line 1, in <module>     gen_arti_bis()   file "<ipython-input-63-da8720093c11>", line 2, in gen_arti_bis     xpos=np.random.multivariate_normal([centerx,centery],np.diag([sigma,sigma]),nbex/2)   file "mtrand.pyx", line 4308, in mtrand.randomstate.multivariate_normal (numpy/random/mtrand/mtrand.c:23108) typeerror: 'float' object unsliceable 

in python 3, division using / operator floating point division, if numbers on both sides of operator integers. in several places you're computing nbex / 2, , passing result argument numpy expects integer.

specifically, np.random.multivariate's last argument supposed either int or tuple of ints. you're passing in float, won't accept, if float's value integer (e.g. 5.0). you're passing float np.ones, function seems handle ok (it ignores fractional part of input number).

the basic fix explicitly perform integer division using // operator. replace each place have nbex / 2 nbex // 2 , should work intended to.

note integer division performed // pick floor value (i.e. rounds down, towards negative infinity). if want round differently in situations, may want division / , convert float result integer round (which round value half way between 2 integers ever 1 even) or math.ceil (which round up).