In order to create a contour graph in matlab, we need to convert to nXn data instead of 1xn.
clc; clear; close all;
% option control
op.resolution = 1000;
% read data
data = readmatrix('wignertxt_111_5e20.xlsx');
x = data(:,1);
y = data(:,2);
z = data(:,3);
% make grid
x1 = linspace(min(x),max(x),op.resolution);
y1 = linspace(min(y),max(y),op.resolution);
% interpolation
[x2,y2] = meshgrid(x1,y1);
z2 = griddata(x,y,z,x2,y2);
% figure
contourf(x2,y2,z2,'LineStyle','none')
colorbar
