A simple C program that can calculate resulting electric gradients from a file and output it into another file in the format <x_position> <y_position> <electric_field_intensity, or electric vector fields in the form <x_position> <y_position> <electric_field_intensity_x> <electric_field_intensity_y>.
The command format is: ElectricField2D.exe <Input file path> <Output file path> <Command>.
For gradient, the command is -g and for vector field it is -vf.
The input file format is:
<size of simulation field> <field precision step> <relative permittivity of space> <proximity to particle ignoring margin> <number of charged particles>
<x position of particle 1> <y position of particle 1> <particle 1 charge in Coulombs>
<x position of particle 2> <y position of particle 2> <particle 2 charge in Coulombs>
...
<x position of particle 2> <y position of particle 2> <particle 2 charge in Coulombs>
Example of input file:
20 0.2 1 0.5 3
0 3 0.000000000016
0 -3 -0.000000000016
0 1 -0.000000000016
Here there are 2 particles with the electric charge of 100 million protons and one with the charge of 100 million electrons.
To view the gradient file in gnuplot you can use:
plot "[Path to output file]" with image
And to view the vector field file in gnuplot you can use:
plot "[Path to output file]" using 1:2:3:4 with vectors head filled