I want to compare two strings from two structs. My Code is like below:
%matlab model scan
[variables] = Simulink.findVars('myModell');
variablesNames =[];
%save the names of all the variables in variablesNames
for t= 1:length(variables)
variablesNames(t).Name = variables(t).Name;
end
%scan workspace
for f = fieldnames(my_workspace)
found = false;
for c = 1:length(variablesNames)
if strcmp(f{c}, variablesNames(c))
found = true;
result = 'Found in Workspace: ';
end
if ~found
result = 'Not found inside Workspace';
end
end
disp(['Workspace Variable: ', sprintf('%-*s',40,f{c}), result]);
end
variablesNames is a struct 1x15 with 1 field
my_workspace is 1x1 struct with 20 fields
I got only one variable as return.
What is wrong in this code?
I don't really understand why are you creating a new struct here: variablesNames(t).Name, therefore I just removed that part.
The modified code just iterates through the variables struct-array and checks whether variable my_workspace has a field with the name of the value stored in the Name field of the currently processed element, using isfield.
[variables] = Simulink.findVars('myModell');
for i = 1:length(variables)
if isfield(my_workspace, variables(t).Name)
result = 'Found in Workspace: ';
else
result = 'Not found inside Workspace';
end
disp(['Workspace Variable: ', sprintf('%-*s', 40, variables(t).Name), result]);
end
Related
I'm trying to exctract some data from a nested structure in a recursive manner. First, I know that this has a field (values) which repeats itself inside the nested structure. Secondly I know that the structure which has those values has only structures as fields. In the below code I've tried to acces the structure.values by searching if my current structure has a field named values. If it has, I put .values at the end of my structure name. If it doesn't have this field, I verify if all the fields are structures. If they are, it means that I will have to consider them further and to extract the values from each one. If the fields are not structures, it means that they are values and I save them into a new simplified structure. Example of fields that I want: S.values.model1.values.mission.values.(alt/list). Currently, with the below code I'm only able to get the values from one field and then I get an error and don't know how to approach further.
Code example:
clear all
clc
S=struct()
S.case='1';
S.type='A';
S.values.model1.case='2'
S.values.model1.type='C'
S.values.model1.values.mission.case='3'
S.values.model1.values.mission.type='D'
S.values.model1.values.mission.values.alt='none'
S.values.model1.values.mission.values.list=2
S.values.model1.values.mission.values.parameter=4
S.values.model1.values.phase.case='4'
S.values.model1.values.phase.type='A'
S.values.model1.values.phase.values.num='all'
S.values.model1.values.phase.values.eq=2
S.values.model1.values.phase.values.unit=4
S.values.model1.values.analysis.case='1'
S.values.model1.values.phase.type='A'
S.values.model1.values.phase.values.nump1.list='all'
S.values.model1.values.phase.values.nump1.table='four'
S.values.model1.values.phase.values.nump1.mean=0
S.values.model1.values.phase.values.nump2.list='none'
S.values.model1.values.phase.values.nump2.table='three';
S.values.model1.values.phase.values.nump2.mean=1
s=S.values.model1;
names=fieldnames(s);
nnames=numel(names);
newStruct={};
[valsi,newstructi]=extractValues(names,s,nnames,newStruct)
function [vals,newStruct]=extractValues(names,vals,nnames,newStruct)
if any(strcmp(names,'values'))
vals=vals.('values');
names=fieldnames(vals)
nnames=numel(names)
[vals,newStruct]=extractValues(names,vals,nnames,newStruct);
end
for j=1:nnames
value(j)=isstruct((vals.(names{j})));
end
if all(value)
for k=1:nnames
vals=(vals.(names{k}));
names=fieldnames(vals);
nnames=numel(names);
[vals,newStruct]=extractValues(names,vals,nnames,newStruct);
end
else
for j=1:nnames
value=(vals.(names{j}));
newStruct.(names{j})=value;
end
end
end
As it is known beforehand what fields are requested you can arrange the subsequent filed names in a cell array and use a loop to extract the value:
names = {'values', 'model1', 'values', 'mission', 'values', 'alt'};
out = S;
for name : names
out = out.(name{1});
end
So that is a loop version of using:
out = S.values.model1.values.mission.values.alt;
EDIT:
If you want to list all field names and all field values you can used these functions:
function out = names(s, p)
if isstruct(s)
out = {};
f = fieldnames(s);
for i = 1:numel(f)
s1 = s.(f{i});
p1 = [p '.' f{i}];
out = [out; names(s1, p1)];
end
else
out = {p};
end
end
function out = values(s)
if isstruct(s)
out = {};
f = fieldnames(s);
for i = 1:numel(f)
out = [out; values(s.(f{i}))];
end
else
out = {s};
end
end
Use them as:
n = names(S, 'S');
v = values(S);
I have a long list of variables in my workspace.
First, I'm finding the potential variables I could be interested in using the who function. Next, I'd like to loop through this list to find the size of each variable, however who outputs only the name of the variables as a string.
How could I use this list to refer to the values of the variables, rather than just the name?
Thank you,
list = who('*time*')
list =
'time'
'time_1'
'time_2'
for i = 1:size(list,1);
len(i,1) = length(list(i))
end
len =
1
1
1
If you want details about the variables, you can use whos instead which will return a struct that contains (among other things) the dimensions (size) and storage size (bytes).
As far as getting the value, you could use eval but this is not recommended and you should instead consider using cell arrays or structs with dynamic field names rather than dynamic variable names.
S = whos('*time*');
for k = 1:numel(S)
disp(S(k).name)
disp(S(k).bytes)
disp(S(k).size)
% The number of elements
len(k) = prod(S(k).size);
% You CAN get the value this way (not recommended)
value = eval(S(k).name);
end
#Suever nicely explained the straightforward way to get this information. As I noted in a comment, I suggest that you take a step back, and don't generate those dynamically named variables to begin with.
You can access structs dynamically, without having to resort to the slow and unsafe eval:
timestruc.field = time;
timestruc.('field1') = time_1;
fname = 'field2';
timestruc.(fname) = time_2;
The above three assignments are all valid for a struct, and so you can address the fields of a single data struct by generating the field strings dynamically. The only constraint is that field names have to be valid variable names, so the first character of the field has to be a letter.
But here's a quick way out of the trap you got yourself into: save your workspace (well, the relevant part) in a .mat file, and read it back in. You can do this in a way that will give you a struct with fields that are exactly your variable names:
time = 1;
time_1 = 2;
time_2 = rand(4);
save('tmp.mat','time*'); % or just save('tmp.mat')
S = load('tmp.mat');
afterwards S will be a struct, each field will correspond to a variable you saved into 'tmp.mat':
>> S
S =
time: 1
time_1: 2
time_2: [4x4 double]
An example writing variables from workspace to csv files:
clear;
% Writing variables of myfile.mat to csv files
load('myfile.mat');
allvars = who;
for i=1:length(allvars)
varname = strjoin(allvars(i));
evalstr = strcat('csvwrite(', char(39), varname, '.csv', char(39), ', ', varname, ')');
eval(evalstr);
end
I have data as a struct with several layers, for example:
data.A.B
The data I want to access is in layer B. But the problem is that field names in B can be different depending on where the data comes from. Therefore I can't just type:
data.A.B.myData
myData is itself a struct
I can use:
fieldnames(data.A)
to find the names, but this doesn't help my much. I would have to write code sections for every possible field name that can occur at this level. And that's just what i trying to avoid.
Is there a way to get down to the data I have (myData) without knowing the field names of B?
Traditionally, you can loop over the fieldnames and perform the search of myData at a specific sub-structure of the struct. However, if you don't know which sub-structure you need to search, then you can perform a recursive algorithm. Below is an example. It will return the first match of myData in the struct or an empty matrix if no match found. The code can be improved to find all matches of myData.
function S2=getmyfield(S1,queriedField)
if isstruct(S1)
% Get all fieldnames of S1
fieldArray=fieldnames(S1);
% Find any match with the queried field. You can also use isfield().
% If there is a match return the value of S1.(queriedField),
% else perform a loop and recurse this function.
matchTF=strcmp(queriedField,fieldArray);
if any(matchTF)
S2=S1.(fieldArray{matchTF});
return;
else
S2=[];
i=0; % an iterator count
while isempty(S2)
i=i+1;
S2=getmyfield(S1.(fieldArray{i}),queriedField);
end
end
else
S2=[];
end
end
Cheers.
You just need a recursive function that checks fieldnames at each level for the structure.
This is roughly what you need (it could be improved to supply the path to the found field).
function [ value, found ] = FindField( rootStruct, fieldName )
%FindField - Find a field with a structure
value = [];
found = 0;
if isstruct( rootStruct )
fields = fieldnames(rootStruct);
for fi=1:length(fields)
if strcmp(fields{fi}, fieldName )
value = rootStruct.(fieldName);
found = true;
return;
end
[value, found ] = FindField( rootStruct.(fields{fi}), fieldName );
if found
return;
end
end
end
end
Usage example:
a.b = 1;
a.b.c = 2;
a.b.d = struct('Index',1,'Special',2);
FindField(a,'d')
ans =
Index: 1
Special: 2
I have function f1 which must contain subfunctions, so I can't use another script:
function vars = f1()
a = 1;
b = 'hello';
c = {[1 2 3]};
currvars = whos; %all variable info
for k = 1:size(currvars, 1)
eval(['vars.(currvars(k).name) = ' currvars(k).name ';']);
end
end
I call the function in a script, and then I create the variables in the script using genvarname() and eval():
vars = f1();
varnames = genvarname(fieldnames(vars));
for k = 1:size(varnames(:),1) %Creates vars with the struct's fieldnames.
eval([varnames{k} ' = vars.' varnames{k} ';']);
end
clearvars vars varnames
I'd like to fit the variable creation process into a function somehow while reading out all the variables only to the script calling it, but I don't want to assign a hundred different variable names to the output. Does anyone have any advice on how to do this?
DON'T CREATE zillions of automatically named variables. This is foolish and terribly poor programming style. Instead, learn to use arrays. Multidimensional arrays, cell arrays, struct arrays.
Or, do what you have done, and then be forced to find a kludge like you are looking for.
Take your pick. Eval is evil.
You could return a structure with "corrected" fieldnames:
function output = someFunc
vars = f1();
protected = { %# some list of varnames you don't want
};
names = fieldnames(vars);
newnames = genvarname(names, protected);
for k = 1:numel(newnames)
output.(newnames{k}) = vars.(names{k});
end
end
If you then use
output = someFunc;
varnames = fieldnames(output);
for k = 1:numel(fieldnames)
eval([varnames{k} ' = output.' varnames{k} ';']);
end
in the script/function where you want the variable names, you have a relatively clean way of locking everything up in the function someFunc without having to pre-define all output variable names.
You can also do this in one step:
function someFunc2
vars = f1();
protected = { %# some list of varnames you don't want
};
names = fieldnames(vars);
newnames = genvarname(names, protected);
for k = 1:numel(newnames)
assignin('caller', newnames{k}, vars.(names{k}));
end
end
Which means you just call the function
someFunc2;
in your script, and the function then defines and assigns all the variables in the script's workspace.
A tiny step forward, but forward nonetheless :)
CREDIT TO RODY...
#Old semi-"global" variables:
function vars = f1()
a = 1;
b = 'hello';
c = {[1 2 3]};
currvars = whos; %all variable info
for k = 1:size(currvars, 1)
eval(['vars.(currvars(k).name) = ' currvars(k).name ';']);
end
end
#Function to assign variables to the calling script's/function's workspace. Variable names are determined by the single structure's fieldnames:
function setvars(func)
vars = func;
protected = {'If needed, put variable names you do not want here'};
names = fieldnames(vars);
newnames = genvarname(names, protected);
for k = 1:numel(newnames)
assignin('caller', newnames{k}, vars.(names{k}));
end
end
#Script call:
setvars(f1);
I have written a function that takes the names and values of the input variables and writes them to a file. eg.
a = 10;
b = 100;
writevars('file.txt',a,b);
gives me a file file.txt that contains:
\def\a{\num{10}}
\def\b{\num{100}}
It would now like to be able to pass on all variables that are found using the who command. Eg if who returns:
a b z
I would like to be able to use writevars as if I called writers('file.txt', a, b, z).
The main problem I have is that writevars makes use of inputname... (temporary variables won't work e.g. writevars('file.txt', 100) doesn't work since there is no name to be given in the file).
ANSWER
var_names = who;
for i = 1 : length(var_names)
evalin('caller',['writevars(''file.txt'', ' char(var_names(i)) ' )']);
end
You can use EVALIN to run who from within writevars, e.g.
function writevars(filename,varargin)
%# get a list of variable names in the calling workspace and read their values
if isempty(varargin)
listOfVars = evalin('caller','who');
values = cell(size(listOfVars));
for i=1:length(listOfVars)
values{i} = evalin('caller',listOfVars{i});
end
else
%# use inputname to read the variable names into listOfVars
end
%# --- rest of writevars is here ---
It can be used by using the return value of whos command:
function GetAllVars
a = 45;
x = 67;
ff = 156;
z = who();
for i=1:numel(z)
if ~isequal(z{i},'z')
fprintf(1,'%s = %f\n',z{i},eval(z{i}));
end
end