Plotting 3D vector field with quiver3

[matthew-hennefarth]

I am looking to plot 3D vector fields, though I am having trouble doing so. When I try a very simple example such as:

#include <vector>
#include <matplot/matplot.h>

int main() {

  //specifies location
  std::vector<double> x;
  std::vector<double> y;
  std::vector<double> z;

  //represent the field
  std::vector<double> ex;
  std::vector<double> ey;
  std::vector<double> ez;

  x.push_back(1.0);
  y.push_back(1.0);
  z.push_back(0.0);

  ex.push_back(1.0);
  ey.push_back(0.0);
  ez.push_back(0.0);

  matplot::quiver3(x, y, z, ex, ey, ez);
  matplot::show();
  return 0;
}

the gnuplot window pops up, but nothing is shown and I get the following error:

multiplot> splot  '-' with vectors  linecolor rgb "0x000071BC" dashtype 1 linewidth 0.5 linetype -1
                                                                                                   ^
           line 2: All points x value undefined


multiplot> splot  '-' with vectors  linecolor rgb "0x000071BC" dashtype 1 linewidth 0.5 linetype -1
                                                                                                   ^
           line 4: All points x value undefined

I am not sure if I am calling the function correctly, or what I am doing wrong; but I would love to get this working! Let me know what I need to fix to get this working!

[alandefreitas]

Does this example work? It might serve as a starting point.

[matthew-hennefarth]

I had read through it, but the function call is using the Z surface, with an implicitly defined x,y coordinate scheme. I have explicit x,y,z positions for each vector. Though, I was able to get it working by normalizing my vectors first, and then scaling them!

Also, I noticed that there is no colormap feature for vectors at the moment (please correct me if I am wrong) and I have forked the repo and am working on adding this right now. I can submit a pull request to add this feature, let me know!

[alandefreitas]

I had read through it, but the function call is using the Z surface, with an implicitly defined x,y coordinate scheme. I have explicit x,y,z positions for each vector. Though, I was able to get it working by normalizing my vectors first, and then scaling them!

I see. Good to know it worked somehow. It's been a while since these plot types were implemented so I'd have to check the code and come up with some examples to be sure about these problems.

Also, I noticed that there is no colormap feature for vectors at the moment (please correct me if I am wrong) and I have forked the repo and am working on adding this right now. I can submit a pull request to add this feature, let me know!

That's true. Sure. PRs are more than welcome.