How should I format my .dat file so that a 3D vector plot can be made?

Question

I\'m working this programming task for college where we have to write a c++ program that calculates the magnetic field vector for certain coils in 3D space.

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Answer 1

I made this simple example to show you how to draw a vector field. The output would be something like this pic:

The data example I used to plot this was:

# Px    Py    Pz    Bx    By    Bz
  0     0     0     0.8   0.8   0.45
  0     0     1     0.5   0.7   0.35
  0     0     2     0.7   0.5   0.25
  0     1     0     0.65   0.65   0.50
  0     1     1     0.6   0.6   0.3
  0     1     2     0.45   0.45   0.20
  1     0     0     0.5   0.7   0.35
  1     0     1     0.75   0.75   0.4
  1     0     2     0.85   0.85   0.25
  1     1     0     0.90   0.85   0.23
  1     1     1     0.95   0.86   0.20
  1     1     2     0.98   0.88   0.13
  2     0     0     0.73   0.83   0.43
  2     0     1     0.53   0.73   0.33
  2     0     2     0.73   0.53   0.23
  2     1     0     0.68   0.68   0.52
  2     1     1     0.63   0.57   0.23
  2     1     2     0.48   0.42   0.22

The command to plot it is:

gnuplot> splot "./data3d.dat" with vectors

Now you should read the section 44, page 53 of the official manual (and here the pdf). You may find this site also very useful.

Edited:

This command doesn't fit into your description: mapping from (x,y,z) to (t,u,v). It actually does this mapping: from (X,Y,Z) to (X+dX,Y+dY,Z+dZ).

Cheers, Beco