How is the best choice to import many tables in matlab?

Hi guys!

I'm working with tables importing in matlab. I've a database of 55 tables that store asteroids data and each table has: first line with asteroid name, header line and then data.

I would like to create a structure in matlab to store these tables. So, for example, the first field of structure contains the name of objects, the second field the position data, so x,y and z coordinates.

Something like that:

I managed to import position data, but I've problems to import names, that are positioned at first line and first column of my tables, as follows:

2012_LA

x_km, y_km, z_km

0.325319882863936E+08, -0.149108978103170E+09, 0.627986890338602E+07

0.351222909100528E+08, -0.148486401801382E+09, 0.637551116147345E+07

0.377011274331304E+08, -0.147819660954309E+09, 0.646921156241256E+07

0.402677620652748E+08, -0.147108971725492E+09, 0.656094421089712E+07

0.428214631350452E+08, -0.146354561948634E+09, 0.665068377342624E+07

0.453615032541851E+08, -0.145556671046544E+09, 0.673840548302432E+07

Here is my code with only 2 .csv input file for simplicity:

clc; clear all; close all;
% Import asteroid propagated orbits computed by Fortran program: "NEOs_orbits"
input_path = 'D:\OneDrive\MSc_Thesis\Projects\NEOs_orbits\OutputFiles\';
%Automatic .txt file detection in the aboved specified folders
files_ast_orbits = dir([input_path, '\*.csv']);

% Failed attempt to import asteroid name
%ast_database.pdes = readtable(fullfile(input_path,files_ast_orbits(36).name),"Range",'A1:A1')

for i = 1:numel(files_ast_orbits)
    ast_database(i).pos = table2struct(readtable(fullfile(input_path,files_ast_orbits(i).name)));
end

Can you help me to also import asteroid names?

Can you give me your opinion about this structure? Is there a better way to create database made of many tables?

Answer 1

[Voss]

% input_path = 'D:\OneDrive\MSc_Thesis\Projects\NEOs_orbits\OutputFiles\';
input_path = '.';
files_ast_orbits = dir(fullfile(input_path,'*.csv'));

% initialize a struct array with name and pos fields
ast_database = repmat(struct('name','','pos',[]),1,numel(files_ast_orbits));

for i = 1:numel(files_ast_orbits)
    
    % read each file into a cell array
    C = readcell(fullfile(input_path,files_ast_orbits(i).name));
    
    % the name is the contents of the first cell
    ast_database(i).name = C{1};
    
    % convert the name to character vector if it is not already
    if ~ischar(ast_database(i).name)
        ast_database(i).name = num2str(ast_database(i).name);
    end
    
    % make the position data a matrix, store in the 'pos' field
    ast_database(i).pos = reshape([C{3:end,:}],[],3);
    
end

% check it:
ast_database

ast_database = 1×2 struct array with fields:
    name
    pos

{ast_database.name}

ans = 1×2 cell array
    {'459872'}    {'1991_VG'}

ast_database(1).pos

ans = 361×3

1.0e+08 * -0.1377 1.4274 0.1093 -0.1628 1.4261 0.1085 -0.1879 1.4245 0.1076 -0.2130 1.4224 0.1068 -0.2380 1.4199 0.1059 -0.2631 1.4169 0.1049 -0.2881 1.4136 0.1040 -0.3131 1.4098 0.1030 -0.3381 1.4056 0.1019 -0.3630 1.4010 0.1009

Answer 2

[Image Analyst]

Try importdata(). It gives you the header information separate from the numerical data.

[Giuseppe]

Ok. It seems to works, but I have problem with first file because in this case the asteroid name is a number.

Can you help me?

[Image Analyst]

Looks like no name's code works because you accepted his answer.