loop over variable with different characters

Hi,

I wonder if someone cna help me with my problem and that is if I have lets say 4 variables in my workspace with different

characters in the begnning end ends with the same words, for example:

abcd_hpcd_Df

defg_hpcd_Df

hijk_hpcd_Df

lmno_hpcd_Df

I want to write it in matlab in a easier way, just write hpcd_Df and not the characters in the beginning.

[KSSV]

Don't name the variables like that. Use the convention you want.

[Serhat Unal]

Sure, this is just an example, but the real convention is as following:

ijjk_hpcd_Df

byzu_hpcd_Df

hhet_hpcd_Df

vffr_hpcd_Df

its just the 4 words in the beginning that are different, and I want to point out also that one of them are only once being

included in the workspace. To call it I want to use _hpcd_Df and not to check what words it begins with every time.

[Walter Roberson]

What do you want to do with the variables?

[Serhat Unal]

I want to call them and insert them into a table as a column with these variables. The thing is

that each of the variables is among 100 other variables and I dont know what words they begin with

and to look visually and find each is a very time consuming. Therefore when I clean the workspace and insert

new 100 variables I want to write like_hpcd_Df to find the corresponding variable.

[Stephen23]

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Jan]

This shows, that you have created a bunch of variables and stored important information in the name of the variables. This design is a typical DON'T in programming.

But is you do not want to re-design the code from scratch, this might help:

clear variables
abcd_hpcd_Df = 1;
defg_hpcd_Df = 1;
hijk_hpcd_Df = 1;
lmno_hpcd_Df = 1;
abcde        = 2;

VarList = whos;
NameList = {VarList.name};
NameList(endsWith(NameList, '_hpcd_Df'))

ans = 1×4 cell array
    {'abcd_hpcd_Df'}    {'defg_hpcd_Df'}    {'hijk_hpcd_Df'}    {'lmno_hpcd_Df'}

[Serhat Unal]

Alright this is the solution that I want, but I have now another problem from this and that is how

can I access the data from the tables?. Lets say If I want to show the data for each variable in a table.

[Jan]

This would be much easier, if you decide for another design, which does not populate the workspace with many variables, but store them in a struct. eval is a shot in your knee. TUTORIAL: Why and how to avoid Eval

Sigh.

abcd_hpcd_Df = 1;
defg_hpcd_Df = 1;
hijk_hpcd_Df = 1;
lmno_hpcd_Df = 1;
abcde        = 2;

VarList  = whos;
NameList = {VarList.name};
NameList = NameList(endsWith(NameList, '_hpcd_Df'));

T = table();
for k = 1:numel(NameList)
    T.(NameList{k}) = eval(NameList{k});  % BAD, don't blame me
end
T

T = 1×4 table
    abcd_hpcd_Df    defg_hpcd_Df    hijk_hpcd_Df    lmno_hpcd_Df
    ____________    ____________    ____________    ____________

         1               1               1               1      

[Serhat Unal]

This is the exact answer to my question. Thanks alot!

[Stephen23]

abcd_hpcd_Df = 1;
defg_hpcd_Df = 1;
hijk_hpcd_Df = 1;
lmno_hpcd_Df = 1;
abcde        = 2;
save('mydata.mat','-regexp','_hpcd_Df$')
S = load('mydata.mat')

S = struct with fields:
    abcd_hpcd_Df: 1
    defg_hpcd_Df: 1
    hijk_hpcd_Df: 1
    lmno_hpcd_Df: 1