How to incorporating a dataset in the form of a struct into a function in a for loop?

Hello everyone!

I'm new in MATLAB. I want to analyze some kinematics and include some data in the struct into a new struct by including it in a function inside the for loop. I have lots of variables with different names. So, I wrote some codes with applicable this situation.

But when I try to run this code getting some errors. I have added codes and error. Please explain to me where i do wrong and how can i fix it. Thank you for your helps.

Here are some details:

I got the struct named "dataset" with another code.

My variables are struct which like "dataset.fileName.movName.repName.fTime.dataName.segName.rotName". The end point of this struct is a matris.now, I want to create a variable as a new struct by automatically inserting the matrix data in this "dataset.fileName.movName.repName.fTime.dataName.segName.rotName" structure into another function.

My transformation formula

%% My transformation formula 
x = linspace(0, 100, length(your_data));
y = 0:100;
new_data = spline(x, your_data, y);

I want to put a " dataset.fileName.movName.repName.fTime.dataName.segName.rotName" variable in "your_data" section and create a new data like this " normalized.fileName.movName.repName.fTime.dataName.segName.rotName"

%% My code
fileName= {'name'};
nameExt= {'dataset.'};
snameExt= string(nameExt);
nfileName= string(fileName);

for i1= 1:length(nfileName)
    movName={'HandToHead'};
    nmovName= string(movName);
    for i2=1:length(nmovName)
        repName={'One','Two'};
        nrepName= string(repName);
        for i3=1:length(nrepName)
            fTime={'TO'};%'TS'};
            nfTime= string(fTime);
            for i4=1:length(nfTime)
                segName= {'RShoulder','RElbow','RWrist'};
                nsegName=string(segName);                                 
                for i5= 1:length(nsegName)
                    rotName={'_x','_y','_z'};
                    nrotName=string(rotName);
                    for i6=1:length(nrotName)
                        dataName={'jointAngle','angularVelocity','angularAcceleration'};
                        ndataName= string(dataName);
                        for i7=1:length(ndataName)
                            infileName(i1)= snameExt+nfileName(i1)+'.'+nmovName(i2)+'.'+nrepName(i3)+'.'+nfTime(i4)+'.'+ndataName(i7)+'.'+nsegName(i5)+nrotName(i6);
                            for k=1:length(infileName)
                                A=[];
                                B=[];
                                B(k)= (infileName(k));
                                x = linspace(0, 100, length((B(k))));
                                y = 0:100;
                                A(k)= spline(x,(B(k)),y);
                                Normalized.(infileName(k))=(A(k));
                            end
                        end
                    end
                end
            end
        end
    end
end

Error text:

Error using chckxy (line 30)
The first two inputs must have at least two elements.

Error in spline (line 72)
[x,y,sizey,endslopes] = chckxy(x,y);

Error in normalize (line 33)
                                A(k)= spline(x,(B(k)),y);

[Stephen23]

Why are you defining cell arrays of character vectors, which you immediately convert to string arrays?

Why not just define string arrays right from the start, i.e. replace this

segName= {'RShoulder','RElbow','RWrist'};
nsegName=string(segName); 

with simpler:

nsegName = ["RShoulder","RElbow","RWrist"];

"Please explain to me where i do wrong and how can i fix it."

Most likely the answer to your question is to replace this incorrect approach:

infileName(i1)= snameExt+nfileName(i1)+'.'+nmovName(i2)+'.'+nrepName(i3)+'.'+nfTime(i4)+'.'+ndataName(i7)+'.'+nsegName(i5)+nrotName(i6)

with the correct syntax for accessing fields of a structure:

https://www.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html

Just because you join lots of text together so that it looks like code, does not turn it into code.

Although it can be made to work, it leads to very complex, inefficient, obfuscated code. Much better is to read the MATLAB documentation and this forum to find the correct syntax for doing whatever that required task is.

[Mert Dogan]

@Stephen thank you for your responding.

As an inexperienced person in Matlab, it is normal for me to write faulty "codes." (or what term you say rather than code).

fileName = it determines patients name surname, I have 40 patients.

movName= I recorded daily living activities of kinematics. So I have 13 different daily task.

repName= it determines repetition number of movement. I recorded 3 times of each tasks.

fTime= it determines time period of data. (pre-treatment-post-treatment) i have 2 different

dataName= it determines data type, (jointAngle, angular Velocity, angular Acceleration) i have 3 different conditions

segName= it determines joints name ( i have 22 joints)

rotName= it determines movement axis. (i have 3 axis).

I must to manage this data for a newbie. There are just 617760 variable names. Also, these data are made up of different matrices, and now I'm trying to create an automated code to process them.

Have you any suggestion for this situation? Can you explain some examples your suggestions?

[Stephen23]

"...it is normal for me to write faulty "codes." (or what term you say rather than code)."

I did not write anything about "faulty" code.

I wrote that text that looks like code is not the same thing as code.

Your question shows that you joined lots of text together into something that looks the same as some code. But, as I wrote, some text (e.g. character vector, string) that looks like code is not code. It is certainly possible to evaluate that text as if it were code, but in almost all cases the much simpler and much more efficient approach is to write actual code (e.g. using the syntax in the link I gave you), not to create some text that looks like code.

"Have you any suggestion for this situation?"

Apparently you have nested structures and want to loop over their fieldnames.

As I wrote in my last comment, for that you can use dynamic fieldnames: see the link I gave you (it has examples).

[Mert Dogan]

@Stephen

Hey Stephen,

I solved my problem with your suggestions.

Thank you a lot!