Creating a vector from two points using 3 coordinates
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I'm trying to create two vectors from two points created from a set of data. The data set contains 3106 values. I need something like a loop for this to work, so i can plot the length of these two vectors over time.
fyi: The vectors are the force projected on the ground while running.
In the end I need an array of the length of both vectors.
This is what i got so far:
j = 1:10:length(Data.Time)
x0_l=Data.XPC_FP1COP(j,1);
y0_l=zeros(length(Data.Time),1);
z0_l=Data.XPC_FP1COP(j,2);
x0_r=Data.XPC_FP2COP(j,1);
y0_r=zeros(length(Data.Time),1);
z0_r=Data.XPC_FP2COP(j,2);
x_l=Data.XPC_FP1GRF(j,1);
y_l=Data.XPC_FP1GRF(j,1);
z_l=Data.XPC_FP1GRF(j,1);
x_r=Data.XPC_FP2GRF(j,1);
y_r=Data.XPC_FP2GRF(j,1);
z_r=Data.XPC_FP2GRF(j,1);
Ground_l = [x0_l,y0_l,z0_l];
Ground_r = [x0_r,y0_r,z0_r];
Top_l = [x_l,y_l,z_l];
Top_r = [x_l,y_l,z_l];
F_l = Ground_l - Top_l
F_r = Ground_r - Top_r
3 个评论
You haven't actually asked a question, so it's unclear what help you need. You've given us some code (which I don't think will work because the length of the y0_? vectors won't match the length of the x0_? and z0_? vectors) but don't really tell us what it's meant to do.
My understanding is that you have two points moving through a 3D space. And it sounds like the distance between these two points vary in time.
No idea what the length of the line refers to? What line? Do you mean that you want to plot the distance between the two points with time?
And by distance, do you mean euclidean distance (i.e 
)?
)?采纳的回答
I think this would complete your code.
Times=1:10:length(Data.Time);
J=numel(Times);
F=nan(J,3);
for j = 1:J
x0 = Data.XPC_FP1COP(j,1);
y0 = zeros(length(j),1);
z0 = Data.XPC_FP1COP(j,2);
x = Data.XPC_FP1GRF(j,1);
y = Data.XPC_FP1GRF(j,2);
z = Data.XPC_FP1GRF(j,3);
Start = [x0,y0,z0];
End = [x,y,z];
F(j,:) = End - Start;
end
plot(vecnorm(F,2,2))
1 个评论
Guillaume
2019-6-12
Is there any point to the loops? I would assume that:
rows = 1:10:numel(Data.Time); %and if Data is a table use height(Data)
F = Data.XPC_FP1GRF(rows, 1:3) - [Data.XPC_FP1COP(rows, 1), zeros(numel(rows), 1), Data.XPC_FP1COP(rows, 3)];
plot(vecnorm(F, 2, 2));
would achieve the same result.
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