Nested loop creating two dimensional cell

Hello,

I am writing a processing script, and I'm still pretty novice at MATLAB so any help would be appreciated. I have 10 participants in my data, and each participant has 9 trials of conditions. I want to use a loop to make a 10x9 cell where each cell is a 1x1 structure. With my current nested loop, the output IS a 10x9 cell where each cell is a 1x1 structure, BUT each cell in the first column of the only gives the first condition repeated over and over again for the first participant, and each cell in the second column only gives the first condition repeated over and over again of the second participant, etc. (as opposed to each column being a different condition and each row being a different participant). Does anyone know how I can fix it? The code is as follows:

lCond = length(triallist);
wCond = width(triallist);
for i=1:lCond
    for j = 1:wCond
        filename = triallist{j};
        calcdata{i,j} = calc_splitbelt(filename,slowleg);
    end       
end

triallist is all of my data files, organized with conditions each being separated with a comma to create new columns and participants being separated with a semicolon to create new rows.

Answer 1

[Geoff Hayes]

@Marisa Mulvey - looking closely at your inner loop

for j = 1:wCond
    filename = triallist{j};
    calcdata{i,j} = calc_splitbelt(filename,slowleg);
end      

while the filename changes on each iteration of the loop BUT there is no dependence on i. So if we consider each row in the first column where j equals 1 then

% for i == 1, j == 1
filename = triallist{1};
calcdata{1,1} = calc_splitbelt(filename,slowleg);

% for i == 2, j == 1
filename = triallist{1};
calcdata{2,1} = calc_splitbelt(filename,slowleg);

% for i == 3, j == 1
filename = triallist{1};
calcdata{3,1} = calc_splitbelt(filename,slowleg);

% etc.

then we see that each row in the first column is calculated the same way. This will be true for all columns. How should the participant i be used in this calculation? What is the format for the data in the triallist?

[Marisa Mulvey]

Hi Geoff,

Oh, I see! That makes sense why it's repeating when it shouldn't. When I make it triallist{i,j} though my error is that it is not scalar. This is how my triallist is formatted

triallist = {...

'CSB_YA001_control0008.mat', 'CSB_YA001_control0009.mat', 'CSB_YA001_control0010.mat', 'CSB_YA001_control0011.mat', 'CSB_YA001_control0012.mat', 'CSB_YA001_control0013.mat', 'CSB_YA001_control0014.mat' [], [];

'CSB_YA002_control_0008.mat', 'CSB_YA002_control_0009.mat', 'CSB_YA002_control_0010.mat', 'CSB_YA002_control_0011.mat', 'CSB_YA002_control_0012.mat', 'CSB_YA002_control_0013.mat', 'CSB_YA002_control_0014.mat', [], [];

'CSB_YA003_control_0008.mat', 'CSB_YA003_control_0009.mat', 'CSB_YA003_control_0010.mat', 'CSB_YA003_control_0011.mat', 'CSB_YA003_control_0012.mat', 'CSB_YA003_control_0013.mat', 'CSB_YA003_control_0014.mat', 'CSB_YA003_control_0015.mat', 'CSB_YA003_control_0016.mat';

'CSB_YA004_control_0008.mat', 'CSB_YA004_control_0009.mat', 'CSB_YA004_control_0010.mat', 'CSB_YA004_control_0011.mat', 'CSB_YA004_control_0012.mat', 'CSB_YA004_control_0013.mat', 'CSB_YA004_control_0014.mat', 'CSB_YA004_control_0015.mat', 'CSB_YA004_control_0016.mat';

'CSB_YA005_control_0008.mat', 'CSB_YA005_control_0009.mat', 'CSB_YA005_control_0010.mat', 'CSB_YA005_control_0011.mat', 'CSB_YA005_control_0012.mat', 'CSB_YA005_control_0013.mat', 'CSB_YA005_control_0014.mat', 'CSB_YA005_control_0015.mat', 'CSB_YA005_control_0016.mat';

'CSB_YA006_control0010.mat', 'CSB_YA006_control0011.mat', 'CSB_YA006_control0012.mat', 'CSB_YA006_control0013.mat', 'CSB_YA006_control0014.mat', 'CSB_YA006_control0015.mat', 'CSB_YA006_control0016.mat', 'CSB_YA006_control0017.mat', 'CSB_YA006_control0018.mat';

'CSB_YA007_control_0001.mat', 'CSB_YA007_control_0002.mat', 'CSB_YA007_control_0003.mat', 'CSB_YA007_control_0004.mat', 'CSB_YA007_control_0005.mat', 'CSB_YA007_control_0006.mat', 'CSB_YA007_control_0007.mat', 'CSB_YA007_control_0008.mat', 'CSB_YA007_control_0009.mat';

'CSB_YA008_control_0001.mat', 'CSB_YA008_control_0002.mat', 'CSB_YA008_control_0003.mat', 'CSB_YA008_control_0004.mat', 'CSB_YA008_control_0005.mat', 'CSB_YA008_control_0006.mat', 'CSB_YA008_control_0007.mat', 'CSB_YA008_control_0008.mat', 'CSB_YA008_control_0009.mat';

'CSB_YA009_control_0001.mat', 'CSB_YA009_control_0002.mat', 'CSB_YA009_control_0003.mat', 'CSB_YA009_control_0004.mat', 'CSB_YA009_control_0005.mat', 'CSB_YA009_control_0006.mat', 'CSB_YA009_control_0007.mat', 'CSB_YA009_control_0008.mat', 'CSB_YA009_control_0009.mat';

'CSB_YA010_control_0001.mat', 'CSB_YA010_control_0002.mat', 'CSB_YA010_control_0003.mat', 'CSB_YA010_control_0004.mat', 'CSB_YA010_control_0005.mat', 'CSB_YA010_control_0006.mat', 'CSB_YA010_control_0007.mat', 'CSB_YA010_control_0008.mat', 'CSB_YA010_control_0009.mat'};

[Geoff Hayes]

@Marisa Mulvey - can you post the full error message? If I take your above code, it will create a 10x9 cell array and there is no error when I do something like

triallist{1,2}

Perhaps your i or j are invalid? What are lCond and wCond initialized to?

[Marisa Mulvey]

Hi Geoff,

My error that I receive for the loop is:

Error using load

Must be a text scalar.

I think I figured it out. I think it's because YA001 and YA002 only have 7 conditions instead of 9, so the final 2 conditions for those participants in the triallist is [] [] instead of a file. You're right that it's not a loop issue. Thank you so much for your help!

[Geoff Hayes]

Glad I was able to help, Marisa!