Proper way to plot a linear combination

General Usage
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1

Hello, good afternoon.

Im trying to plot a linear combination in a 3d plane, subset of two vectors, with julia and plots and I’m failing with this tasks. Julia plots works a bit different than matplotlib.
What is the correct way to do that?

let
	gr()
	# x-axis range
	xlim = [-4,4];
	a = [3, 5, 1];
	b = [0, 2, 2];

	xscalars = rand(xlim[1]:xlim[2], 100);
	@info xscalars;
	
	yscalars = rand(xlim[1]:xlim[2], 100);
	@info yscalars;
	
	c = [(a * xs) + (b .* ys) for (xs, ys) in zip(xscalars, yscalars)];
	@info c;
	
	scatter(a, b, c)
end

image

2

I think you want:

scatter(Tuple.(c))

but this is the workaround to plot vectors of vectors as points with GR. With other backends that might be different.

2 Likes
3

Seems to work with ploty also.
I’ll check the points to see if there are any issues.

image

4

It worked. I’ll never find this solution for this plot. Thank you. An vector of vectorts would never do that in plots.

5

Note that you could avoid the vector of vectors and generate x, y, z components from the start. See the simple method below using a generator expression:

using Plots; gr()
xlim = -4:4
a, b = [3, 5, 1], [0, 2, 2]
xs, ys = rand(xlim, 100), rand(xlim, 100)
x, y, z = (a*xs + b*ys for (a,b) in zip(a,b))
scatter(x, y, z)
1 Like