function [Creal,matrix] = calccap(infile)
% Permitivity of free space.
E_0 = 8.854187818E-12;
% Read in the panels
[panels] = readpanels(infile);
done = 'read input file'
% Compute the panel centroids and areas (don't need the normals).
[centroids, normals, areas] = gencolloc(panels);
done = 'generated collocation points'
% Generate the collocation matrix
[matrix] = collocation(panels,centroids);
done = 'generated matrix'
% Create the rhs
[r,c] = size(matrix);
rhs = ones(r,1);
% Solve for the charge density vector
q = matrix \ rhs;
done = 'solved for charge'
% Integrate the charge over the surface to compute the capacitance.
% But first multiply the charge density by the panel area.
q = q .* areas.';
C = sum(q);
% Scale the capacitance by the free space dielectric permitivity and 4pi.
Creal = E_0 * 4 * pi * C;