Finding the Dot Product of Two Vectors

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The dot product (or scalar product) of two vectors is used, among other things, as a way of finding the angle theta between two vectors. Recall that, given vectors a and b in space, the dot product is defined as
a . b = | a | | b | cos( theta )
We will use this formula later to find the angle theta. For now, we want to focus on the computation formula for the dot product: given the components of the vectors a = < a1, a2, a3 > and b = < b1, b2, b3 >, the dot product is given by
a . b = a1*b1 + a2*b2 + a3*b3
Remember that in both cases, the result is NOT a vector, but a scalar (or number-hence the alternate name "scalar product").
Use this formula to write a function file which computes the dot product of two 3-dimensional vectors a and b. The function name is DotProd, which has two inputs: the vectors a and b (which should contain 3 elements each). The output is the single value y, which is a . b
NOTE: Though not assessed, it may be more efficient if you use element by element multiplication along with MATLAB's built-in command sum (which adds the components of a vector).
Your Function
function y = DotProd(a,b) % NOTE: DO NOT CHANGE THE CODE ON THIS LINE!
y = ;
end
so please can i have the Code to call my function ?
  1 个评论
Guillaume
Guillaume 2019-5-30
so please can i have the Code to call my function ?
No, we don't you your homework for you (particularly ones as easy as this).

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回答(2 个)

Piyush kant
Piyush kant 2019-5-30
I hope this works.
function y = DotProd(a,b) % NOTE: DO NOT CHANGE THE CODE ON THIS LINE!
y = a.*b ;
end
  5 个评论
Walter Roberson
Walter Roberson 2019-5-30
maryam alhajji comments to Guillaume:
please respect , as the it is practice not homework , and if I know the answer I will not ask someone to help me , I am just asking for the knowledge .
Walter Roberson
Walter Roberson 2019-5-30
You could read the documentation: the code for the simple case is given there.

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maryam alhajji
maryam alhajji 2019-5-30
编辑:Walter Roberson 2019-5-30
syms a1 a2 a3 b1 b2 b3
a=[ a1 , a2 , a3];
b= [ b1 , b2 , b3];
d= dot(a,b)
c=cross (a,b)
c =
[ a2*b3 - a3*b2, a3*b1 - a1*b3, a1*b2 - a2*b1]
# the answer shoe me by (-) and i donot know how to keep it as
function y = DotProd(a,b) % NOTE: DO NOT CHANGE THE CODE ON THIS LINE!
y = ;
end
# if any one can help me I am thankful .

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