How to load multiple *.mat files in a directory into individual 271x1 vectors. Not structures. Need them named dynamically. Don't crucify me.
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Ok, so yes, I know, DONT USE DYNAMIC VARIABLES!!!!
I totally understand why this would not be good in functions and scripts and all that. In fact, if I try to even think about implementing something like that, my head hurts and says "nope, just stop".
However in this situation I need dynamic variables, unless someone else can think of a better way.
I am processing field data from gas concentration measurements. The important data I need to look at is the concentration curve. For my two day survey I have say one vector that's about 40000x1 in size. This gets broken down into 300x1 pieces for the observations at different sites. So, I end up with about 72 individual 300x1 vectors. Each comes from a different location (eg ccf1 ccf1 cc1 cc2 st1 st2 etc etc etc etc). I have written each 300x1 vector to a *.mat file named after the site (eg ccf12.mat) .
Now, I want to look at each using cftool and play with curve fittings. However, cftool only takes in vectors. You can't access structures or tables (otherwise I would def go that route). SO I am trying to import all the *.mat files in the directory and name the output variables accordingly. However they keep ending up being structures. I'm just using a simple loop:
a=dir('*mat');
for i = 1:length(a)
b=load(a(i).name);
eval([char(a(i).name) '= [b.co2_umolm3(:)]']) %%%trying to not have it output a structure by calling the variable itself
clear b
end
All the variables are loaded, with their fancy dynamic names. But all are structures with a variable mat, like cc14.mat would be the data. Then if I want to add to the loop a step to try and change the structure to a vector I encounter the annoying aspect of dynamic variables in that I have to continue to use eval.
This isn't something that will be in a code or used often. It's just for some data exploration and curve fitting testing. Hence I am not concerned about using dynamic variables. But this structure thing is driving me nutts. Any suggestions (Aside from DONT USE DYNAMIC VARIABLES).
Cheers
回答(2 个)
Steven Lord
2020-10-15
How do you distinguish the X and Y data stored in each MAT-file? Or do you have a 271-by-N variable stored in each MAT-file, with one of the columns being your Y data and the rest being the X data?
>> data = load('census.mat')
data =
struct with fields:
cdate: [21×1 double]
pop: [21×1 double]
>> xdata = data.cdate;
>> ydata = data.pop;
% Now work with xdata and ydata
If you don't know the names of your X and Y data variables but can distinguish them when you see them:
data = load('census.mat');
variablesFromFile = fieldnames(data);
for whichVariable = 1:numel(variablesFromFile)
name = variablesFromFile{whichVariable};
V = data.(name);
if isXData(V) % You need to write this, maybe with name being an additional input
xdata = V;
elseif isYData(V) % You need to write this
ydata = V;
else
% how do you want to handle the other data in the file? Ignore it?
end
end
% Now work with xdata and ydata
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Mathieu NOE
2020-10-15
Hi
though I am not really an expert in this kind of field, I did long time ago something in that area . don't know, but maybe in my code below you would see how to proceed
Good luck !
% eval(['load ' Filenameshort '.MAT']);
MyStruct = load([Filenameshort '.MAT']);
fn = fieldnames(MyStruct);
VariableName = char(fn);
%%%%%%%%%%
% % si le nom du fichier .mat n'a pas été renommé apres acquisition alors le nom de la structure est idem nom du fichier
% if isempty(VariableName)
% VariableName = lower(Filenameshort);
% end
%
% Initialisation
VarName = [];
ind_comma = [];
ind_bracket = [];
ind_value = [];
% Axe temporel
%time = long_capture.X.Data;
time = eval(['MyStruct.' VariableName '.X.Data']); % temps en secondes
nsamples = length(time);
% capture des data
commandeIM = zeros(nb_outputs*nb_harmo,nsamples);
commandeRE = zeros(nb_outputs*nb_harmo,nsamples);
residuelIM = zeros(nb_inputs*nb_harmo,nsamples);
residuelRE = zeros(nb_inputs*nb_harmo,nsamples);
freq = zeros(1,nsamples);
% calcul du nombre de variables
nb_var = length(eval(['MyStruct.' VariableName '.Y']));
for ci = 1:nb_var
VarName = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Name']);
ind_bracket1 = findstr(VarName ,'['); % détetction bracket "ouverture"
ind_comma = findstr(VarName ,','); % détetction virgule
ind_bracket2 = findstr(VarName ,']'); % détetction bracket "fermeture"
ind_value1 = str2num(VarName(1,ind_bracket1+1:ind_comma-1));
% cas particulier nb_inputs = 1 alors ind_value1 = [], à remplacer par 1
if isempty(ind_value1), ind_value1 =1;end
ind_value2 = str2num(VarName(1,ind_comma+1:ind_bracket2-1));
% cas particulier nb_outputs = 1 alors ind_value2 = [], à remplacer par 1
if isempty(ind_value2), ind_value2 =1;end
ind_value = max(ind_value1,ind_value2); % ex [1,10] ou [10,1] => 10
% ind_value_table1 = [ind_value_table1; ind_value];% debug only
if ~isempty(findstr(VarName,'commandeIM'))
commandeIM(ind_value,:) = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Data']);
elseif ~isempty(findstr(VarName,'commandeRE'))
commandeRE(ind_value,:) = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Data']);
elseif ~isempty(findstr(VarName,'freq'))
freq = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Data']);
elseif ~isempty(findstr(VarName,'residuelIM'))
residuelIM(ind_value,:) = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Data']);
elseif ~isempty(findstr(VarName,'residuelRE'))
residuelRE(ind_value,:) = eval(['MyStruct.' VariableName '.Y(' num2str(ci) ').Data']);
end
end
residuel = residuelRE+j*residuelIM;
commande = commandeRE+j*commandeIM;
freq = double(freq);
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