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Quant版 - 面试题求教
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1 (共1页)
K*V
发帖数: 192
1
Let x, y be uniformly distributed on [0,1] and separate the unit interval [0
,1] into 3 pieces, what is the probability that the 3 pieces of the line can
be constructed into a right-angled triangle?
K*V
发帖数: 192
2
如果只是一般三角形还好,但是right-angled就不会了。

[0
can

【在 K*V 的大作中提到】
: Let x, y be uniformly distributed on [0,1] and separate the unit interval [0
: ,1] into 3 pieces, what is the probability that the 3 pieces of the line can
: be constructed into a right-angled triangle?

k*****n
发帖数: 117
3
0

【在 K*V 的大作中提到】
: 如果只是一般三角形还好,但是right-angled就不会了。
:
: [0
: can

K*V
发帖数: 192
4
别闹了!

【在 k*****n 的大作中提到】
: 0
k*****n
发帖数: 117
5
Did not!
>>> f = lambda (x,y): min( abs(np.array([ x*x, (y-x)*(y-x), (1-y)*(1-y) ])*2
.0 - x*x-(y-x)*(y-x)-(1-y)*(1-y)) ) < 1e-9
>>> data = np.random.rand(1000000,2)
>>> sum( map( f, data ) )
0
Here's why:
for each x, there is at most 2 possible y value to form right triangle.
in x-y plane, your sample space is the unit square (0,0) to (1,1)
but your outcome space is only two 1-d curves.
The probability is 0.

【在 K*V 的大作中提到】
: 别闹了!
K*V
发帖数: 192
6
hehe.It seems make sense...........
Thanks!

*2

【在 k*****n 的大作中提到】
: Did not!
: >>> f = lambda (x,y): min( abs(np.array([ x*x, (y-x)*(y-x), (1-y)*(1-y) ])*2
: .0 - x*x-(y-x)*(y-x)-(1-y)*(1-y)) ) < 1e-9
: >>> data = np.random.rand(1000000,2)
: >>> sum( map( f, data ) )
: 0
: Here's why:
: for each x, there is at most 2 possible y value to form right triangle.
: in x-y plane, your sample space is the unit square (0,0) to (1,1)
: but your outcome space is only two 1-d curves.

r*******t
发帖数: 8550
7
veli smart!

【在 k*****n 的大作中提到】
: 0
t********t
发帖数: 1264
8
别闹,拿measure theory 101来当面试题,羞辱人啊
1 (共1页)
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