how to find cityblock distance?

how to find the city block distance between feature vectors to query image feature vector, in matlab2013?

Answer 1

[Jan]

pdist and pdist2 can calculate the city block distance.

Answer 2

[Fowzi barznji]

x=[1 3 9 6 4 2 6 8 3 6];

y=[4 -2 6 8 8 3 7 2 1 1];

cityblockvalue = sum((abs(x - y)));

cityblockvalue= 32

[Fowzi barznji]

so u can use

cityblockvalue = pdist2(X,Y,'cityblock');

same result

[Image Analyst]

This will give the "as the crow flies" city block distance. If you have a path that is not directly from point A to point B in a straight line, for example a spiral, then you'll have to actually follow the path and sum up the delta x and delta y as you step along the path from one point to the next. That is probably not the case you have, but I'm just mentioning it for completeness.

[Fowzi barznji]

100% right

thanks to your skill

[rema]

hi ,please how applied city block distance if have two vecter such as

a=[1,2,3]

b=[4,5,6;

7,8,9;

10,11,12]

[Rik]

You don't have two vectors, you have a vector and a matrix. The numbere of elements also doesn't match. What would you do if you had to calculate this by hand?

[DGM]

b is not a vector. It depends what the relationship between a and b is.

Assuming that a is a row vector and applies in whole to each row of b in the same way, then the distance for each row is:

x = [1 2 3];
y = [4 5 6; % i made this 4x3 so that it's easy to see the orientation
    7 8 9;
    10 11 12;
    13 14 15];

D = pdist2(x,y,'cityblock').'

D = 4×1

9 18 27 36

D = sum((abs(x - y)),2) % works R2016b+

D = 4×1

9 18 27 36

[rema]

thank you

Answer 3

[Fowzi barznji]

try these files

may be contain an interest to u

[rema]

hi,how obtain on lable image for using in classification by using knn

[Rik]

@rema You're asking a completely new question. Have a read here and here. It will greatly improve your chances of getting an answer.