## Set Length of Vector

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### Set Length of Vector

Hi,

Code: Select all
`import mathu = [1, 2]v = [3, 4]def length_squared(u):    return sum([a ** 2 for a in u])def length(u):    return math.sqrt(length_squared(u))def sub(u, v):    return [a - b for a, b in zip(u, v)]def scale_by_scalar(u, scalar):    return [a * scalar for a in u]def dist(u, v):    return length(sub(v, u))def dist_squared(u, v):    return length_squared(sub(v, u))def setlength(u, 1):    return scale_by_scalar(u, 1 / length(u))def norm(u):    return setlength(u, 1)print norm([100, 0])    # gives [1, 0]print dist(u, v)         # 2.82842712475print dist_squared(u, v) # 8`

I get the following error at def setlength(u, 1);, the error is Expected:).

I was following this tutorial: http://noobtuts.com/python/vector and if you look at the section "Setting the Length of a Vector" it has the code written out as I have. What's wrong?

Thanks.
Indiiyana

Posts: 10
Joined: Tue Nov 26, 2013 1:55 am

### Re: Set Length of Vector

That tutorial disappointingly used the lowercase version of L, not 1. It's unfortunately because single letter variable names like that are discouraged specifically because of that (although they're also often not descriptive enough).
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micseydel

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### Re: Set Length of Vector

So you're saying it shouldn't be setlength but it should be setLength? I changed it to that but the same error occurs.
Indiiyana

Posts: 10
Joined: Tue Nov 26, 2013 1:55 am

### Re: Set Length of Vector

No, it should be the letter l, not the digit 1.
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stranac

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Joined: Thu Feb 07, 2013 3:42 pm

### Re: Set Length of Vector

Haha, of course.

My mistake, thanks.
Indiiyana

Posts: 10
Joined: Tue Nov 26, 2013 1:55 am