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FAQ: How can I process a sequence of files?
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How can I process a sequence of files?
3 comentarios
Salah Djerouni
el 15 de Feb. de 2020
Hi Jan
can i ask you some question because i have a problem for save result in matlab
my probleme is i run matlab with three loops (for...end ) and i want to save the result every change iterataion loop.
if you possible to help me .
thanks Jan
Walter Roberson
el 16 de Feb. de 2020
Pre-allocate an output array that is at least 3 dimensions, with one dimension being the number of times the first loop will execute, a second dimension being the number of times the second loop will execute, and the third dimension being the number of times the third loop will execute. Then assign to the output according to how many loop iterations you have done.
For example,
Lvals = [-83, 149, -5, 0, -2, 101];
numL = length(Lvals);
output = zeros(7, 3, numL);
for J = 9:17:11
Jidx = round((J-9)/17) + 1;
for K = 1000:500:2000
Kidx = round((K-500)/500);
for Lidx = 1 : numL
L = Lvals(Lidx);
output(Jidx, Kidx, L) = J.^2 + K/7 + sin(L.^3);
end
end
end
Respuesta aceptada
Jan
el 26 de Dic. de 2012
Editada: Jan
el 8 de Abr. de 2021
3 comentarios
Walter Roberson
el 23 de Jun. de 2019
Each iteration in a separate file could result in hundreds of thousands of files.
persistent fid
if isempty(fid) || isempty(fopen(fid))
fid = fopen('output.txt','wt');
end
fprintf(fid, 'appropriate format', appropriate data) ;
joshua Abam
el 24 de Jun. de 2019
Hi Walter
I seem not to have follow your suggestion can you help by adding some more comments to ease my grap or better still use this example to illustrate it and where best can I possible attached that to a GA code.
function f = gaintobj(x)
f = rastriginsfcn([x(1)-6 x(2)-13]);
f = f + rastriginsfcn([x(3)-3*pi x(4)-5*pi]);
lb = [1 1 -30 -30];
ub = [20 20 70 70];
%%
% Set the integer variables and number of variables.
IntCon = [1 2];
nvar = 4;
%%
% Set options to call the custom output function, and to initially have
% little crossover.
options = optimoptions('ga','OutputFcn',@gaoutputfunround,'CrossoverFraction',0.2);
%%
% For reproducibility, set the random number generator.
rng(10)
%%
% Set the objective function and call the solver.
fun = @gaintobj;
[x,fval] = ga(fun,nvar,[],[],[],[],lb,ub,[],IntCon,options)
Más respuestas (2)
Sean de Wolski
el 29 de Jul. de 2016
Editada: Sean de Wolski
el 29 de Jul. de 2016
In MATLAB R2014b and newer, you can use a datastore to read a sequence of files in a load-analyze-discard manner or in one shot with the readall() command.
1 comentario
Ismail Qeshta
el 11 de Nov. de 2017
Hi all. Thanks for sharing it. How about if my files are in permutations sequence such as, Data11, Data12, Data 13, etc. Also, what if I would like to plot two different files names within a folder? Regards.
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