how to implement loops in a sturcture

i have four nodes, i want to distances between each pair of node. there are four different structures and each one of them has a leader node, as ldr1, ldr2, ldr3 and ldr4. and each leader node per structure is the 13th node. My code is:

ldr1.x = 32;
ldr1.y = 42;
S1(13).x = ldr1.x;
S1(13).y = ldr1.y;

ldr2.x = 10;
ldr2.y = 15;
S2(13).x = ldr2.x;
S2(13).y = ldr2.y;

ldr3.x = 45;
ldr3.y = 50;
S3(13).x = ldr3.x;
S3(13).y = ldr3.y;

ldr4.x = 22;
ldr4.y = 19;
S4(13).x = ldr4.x;
S4(13).y = ldr4.y;

now i want to calculate distance of leader1 with leader2,3,4. similarly distance of leader2 with leader 1,3,4 and so on.

i have used this line:

for k = 1 : 4
dis_ldr1_ldr2 = sqrt((S(k)((13)).x  - S(k+1)((13)).x)^2 + (ldr(k).y  -      ldr(k+1).y)^2);
end

but this line is giving error. Kindly help

Answer 1

[Doug Hull]

There is a lot of indexing and confusion going on here.

I recommend breaking down the problem into smaller, testable pieces. Here is what I mean, but it is untested.

pointAStructure = S(k)
PointAxValue = pointAStructure.x
PointAyValue = pointAStructure.y

pointBStructure = S(k+1)
PointBxValue = pointBStructure.x
PointByValue = pointBStructure.y

deltaX = PointAxValue - PointBxValue;
deltaY = PointAyValue - PointByValue;

distance = sqrt(deltaX^2 + deltaY^2);

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Your naming convention for the structure S1,S2,S3,S4 does not work well:

naming problems in MATLAB

[Anum]

there will be 12 distances need to be determined. i want to summarize it whitin a loop