csv_to_mat.m

%%%%%%%%%%%%%%%%%%%% .csv to .mat file %%%%%%%%%%%%%%%%
% This file reads the .csv file generated by Paraview and arranges it to be
% readable by MATLAB

clear; clc; close all;

cd D:\computations_dir\oscillating_cylinder\aratio0point1_fratio3point5\postProcessing\plot_over_line_time_z_vorticity;

for i = 1:20
    
%% specify your file name here
filename = ['stationary_cylinder_validation_08apr2023_' num2str(i) '.csv'];
%%

delimiter = ',';
startRow = 2;

formatSpec = '%f%f%f%f%f%f%f%f%[^\n\r]';
fileID = fopen(filename,'r');

dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false);
fclose(fileID);

TimeStep = dataArray{:, 1};
Time = dataArray{:, 2};
Points0 = dataArray{:, 3};
Points1 = dataArray{:, 4};
Points2 = dataArray{:, 5};
U0 = dataArray{:, 6};
U1 = dataArray{:, 7};
U2 = dataArray{:, 8};

% Clear temporary variables
clearvars filename delimiter startRow formatSpec fileID dataArray ans;
%% construct a table

augment = [TimeStep,Time,Points0,Points1,Points2,U0,U1,U2];
%yourtable = array2table(augment);
%sorted_table = sortrows(yourtable,[3 4]);
%sorted_array =table2array(sorted_table);

%%

%x = sorted_array(:,3); y = sorted_array(:,4); 
u_velo = augment(:,5); v_velo = augment(:,6); w_velo = augment(:,7);
u_net = sqrt(u_velo.^2+v_velo.^2+w_velo.^2);

xrange = min(augment(:,3)):0.05:max(augment(:,3));
yrange = min(augment(:,4)):0.05:max(augment(:,4));
[xq,yq] = meshgrid(xrange,yrange);

[r,c] = find(u_net == 0);
u_net(r,c) = NaN;
% Interpolate the scattered data on the grid. Plot the results.
vq = griddata(augment(:,3),augment(:,4),u_net,xq,yq);


pcolor(xq,yq,vq); shading interp;
xlabel('x [m]');
ylabel('y [m]');
title('U [m/s], z = 0 plane');
colorbar;
colormap(parula);
writeVideo(writerObj, getframe(gcf));

end
close(writerObj);