An Octave function that reads and parses astorb.dat file that can be downloaded from ftp://ftp.lowell.edu/pub/elgb/astorb.html. Not tested for Matlab

readastrob.m

function [astorb] = readastorb(file)
%READASTORB reads and parses astorb.dat file that can be downloaded from
%  ftp://ftp.lowell.edu/pub/elgb/astorb.html
%
%  [astorb] = readastorb(file)
%  file   File path
%  astorb The structure array that contains following members
%
%  num    Returned asteroid number list
%  names  Returned asteroid name (if any)
%  hmag   H. magnitude (absolute magnitude)
%  argument_of_perihelion
%         Argument of perihelion of the orbit
%  ascending_node
%         Ascending node of the orbit
%  inclination
%         Inclination of the orbit
%  eccentricity
%         Eccentricity of the orbit
%  semimajor_axis
%         Semimajor axis length of the orbit [AU]

f = fopen(file, "r");

names = [];
hmag = [];
argument_of_perihelion = [];
ascending_node = [];
inclination = [];
eccentricity = [];
semimajor_axis = [];

linecount = 1;

while !feof(f)
	line = fgetl(f);

	astorb(linecount).num = sscanf(line(1:6), "%d", 1);
	astorb(linecount).name = line(8:25);
	astorb(linecount).hmag = sscanf(line(43:47), "%f", 1);
	astorb(linecount).argument_of_perihelion = sscanf(line(127:136), "%f", 1);
	astorb(linecount).ascending_node = sscanf(line(138:147), "%f", 1);
	astorb(linecount).inclination = sscanf(line(149:157), "%f", 1);
	astorb(linecount).eccentricity = sscanf(line(159:168), "%f", 1);
	astorb(linecount).semimajor_axis = sscanf(line(170:181), "%f", 1);

	% astorb.dat contains 68000 lines which is too many for a small scale data processing
	linecount = linecount + 1;
	if 10000 < linecount
		break;
	end;
end;

fclose(f);