figure saving in created folder. Error using savepath: invalid or missing path

While running a for loop, I create folders which name depend on the external looping variable (j). Folders creation works just fine, but if I try to save my gcf into the inner folder, I receive an error stating "Error using saveas (line 138)

Invalid or missing path: ../data_analysis/CD_plot/flow_speed_10/CD_plot_#1flow_speed10".

On the other hand, if I try to save my gcf into the current working folder "../data_analysis" or into the mid folder "../data_analysis/CD_plot", the code works fine. I do not understand what the issue is. Could it be that the just created inner folder does not yet pop up as a possible recipient directory? I highly doubt this.

Below, my for loop code.

[status, msg, msgID] = mkdir('CD_plot');
% sz = linspace(1,100,200);

for j = 1:length(sel_speed)

    [status, msg, msgID] = mkdir(sprintf('../data_analysis/CD_plot/ flow_speed_%d', sel_speed(j)));
    dyn_pressure = 0.5 * rho * sel_speed(j) ^ 2; % calculation of dynamic pressure
    div = dyn_pressure * S;
    
    clear k1 k2 k3 k4 k5

    figure('Position', [200, 200, 800, 800])

    title(['CD plot # ', num2str(j), '; Flow Speed: ', num2str(sel_speed(j))],'fontweight','bold','fontsize', 24)
    hold on
    grid on
    xlabel('AoA [deg]','fontweight','bold','fontsize', 20);
    ylabel('CD [ ]','fontweight','bold','fontsize', 20);
    xlim([-10 35])
%     ylim([-7 1])

    for k = 1:length(MyFolderInfo)
        if k == 87 
            continue
        end
         if (exp_value.vel(k) == sel_speed(j)) && (exp_value.inflation(k) == sel_inflation(1))
            scatter(exp_value.aoa(k), exp_value.f_avg(k, 1) / div, 'or', 'filled', 'LineWidth',5)
            if exist('k1','var') == 1
                x_vec = [exp_value.aoa(k1), exp_value.aoa(k)];
                y_vec = [exp_value.f_avg(k1, 1) / div, exp_value.f_avg(k, 1) / div];
                plot(x_vec, y_vec, '--r')
            end
            k1 = k;
         elseif (exp_value.vel(k) == sel_speed(j)) && (exp_value.inflation(k) == sel_inflation(2))
             scatter(exp_value.aoa(k), exp_value.f_avg(k, 1) / div, 'ok', 'filled')
             if exist('k2','var') == 1
                x_vec = [exp_value.aoa(k2), exp_value.aoa(k)];
                y_vec = [exp_value.f_avg(k2, 1) / div, exp_value.f_avg(k, 1) / div];
                plot(x_vec, y_vec, '--k')
            end
            k2 = k;
         elseif (exp_value.vel(k) == sel_speed(j)) && (exp_value.inflation(k) == sel_inflation(3))
             scatter(exp_value.aoa(k), exp_value.f_avg(k, 1) / div, 'om', 'filled')
             if exist('k3','var') == 1
                x_vec = [exp_value.aoa(k3), exp_value.aoa(k)];
                y_vec = [exp_value.f_avg(k3, 1) / div, exp_value.f_avg(k, 1) / div];
                plot(x_vec, y_vec, '--m')
            end
            k3 = k;
         elseif (exp_value.vel(k) == sel_speed(j)) && (exp_value.inflation(k) == sel_inflation(4))
             scatter(exp_value.aoa(k), exp_value.f_avg(k, 1) / div, 'ob', 'filled')
             if exist('k4','var') == 1
                x_vec = [exp_value.aoa(k4), exp_value.aoa(k)];
                y_vec = [exp_value.f_avg(k4, 1) / div, exp_value.f_avg(k, 1) / div];
                plot(x_vec, y_vec, '--b')
            end
            k4 = k;
         elseif (exp_value.vel(k) == sel_speed(j)) && (exp_value.inflation(k) == sel_inflation(5))
            scatter(exp_value.aoa(k), exp_value.f_avg(k, 1) / div, 'og', 'filled')
            if exist('k5','var') == 1
                x_vec = [exp_value.aoa(k5), exp_value.aoa(k)];
                y_vec = [exp_value.f_avg(k5, 1) / div, exp_value.f_avg(k, 1) / div];
                plot(x_vec, y_vec, '--g')
            end
            k5 = k;
         end
    end
    
    legend({'inf. = 0 mL', 'inf. = 60 mL', 'inf. = 90 mL', 'inf. = 120 mL', 'inf. = 30 mL'}, ... 
     'Location','north','Orientation','horizontal','fontsize', 16)
    hold off
    
     saveas(gcf, ['../data_analysis/CD_plot/flow_speed_', num2str(sel_speed(j)),'/CD_plot_#', num2str(j), 'flow_speed', num2str(sel_speed(j))], 'svg');
end

[Walter Roberson]

What is the total length of filename with all directories included?

[Andrea Giordano]

Hello Master,

../data_analysis/CD_plot/flow_speed_10/CD_plot_#flow_speed_10.svg

thank you.

[Walter Roberson]

That is a relative file name. If you expand the name out completely with the C:\ all the way to the end, then what is length() of the resulting name?

[Andrea Giordano]

Uh, sorry. It is exactly 100 characters .

[Walter Roberson]

could I ask you to experiment by changing the # character to _ (underscore)?

[Andrea Giordano]

Yes, Master. Done, but nothing changed. Here you go with the error message. Cheers, Andrea.

Error using saveas (line 138)
Invalid or missing path: ../data_analysis/CD_plot/flow_speed_10/CD_plot_1flow_speed10
Error in data_analysis_multiple_files (line 271)
    saveas(gcf, ['../data_analysis/CD_plot/flow_speed_',
    num2str(sel_speed(j)),'/CD_plot_', num2str(j), 'flow_speed',
    num2str(sel_speed(j))], 'svg');

[Walter Roberson]

Please run this test code:

if ~isdir('..')
    error('Corrupt or very very old file system, missing .. directory entry')
elseif ~isdir('../data_analysis')
    error('No folder ../data_analysis')
elseif ~isdir('../data_analysis/CD_plot')
    error('No folder ../data_analysis/CD_plot')
elseif ~isdir('../data_analysis/CD_plot/flow_speed_10')
    error('No folder ../data_analysis/CD_plot/flow_speed_10')
else
    fprintf('folder path ../data_analysis/CD_plot/flow_speed_10 is okay')
end

[Andrea Giordano]

Error using data_analysis_multiple_files (line 359)
No folder ../data_analysis/CD_plot/flow_speed_10 

Answer 1

[Fangjun Jiang]

This is really dumb.

In your code, the mkdir() line, there is an extra whitespace in front of 'flow_speed'.

So you created a folder called ' flow_speed_10' (with the leading whitespace), but you are looking for folder 'flow_speed_10'

[Andrea Giordano]

Dear all,

Mr. Jiang is correct. Dumb mistake, I apologize for this. I did not notice, I guess the reason is because I was too focused at finding a proper mistake.

Thank you all very much.

Andrea

[Andrea Giordano]

Jiang, can you write this as an answer, so I can accept it?

Answer 2

[Fangjun Jiang]

add "rehash" after the folder is created.

doc rehash

[Andrea Giordano]

thank you, but now the error is this. (I added rehash in the loop cycle, right after creation of inner folder!

Error using saveas (line 138)
Invalid or missing path: ../data_analysis/CL_over_CD_plot/flow_speed_10/CL_over_CD_plot_#1flow_speed10
Error in data_analysis_multiple_files (line 191)
saveas(gcf, ['../data_analysis/CL_over_CD_plot/flow_speed_', num2str(sel_speed(j)),'/CL_over_CD_plot_#', num2str(j), 'flow_speed', num2str(sel_speed(j))], 'svg');
Error in run (line 91)
evalin('caller', strcat(script, ';')); 
>> 

[Fangjun Jiang]

Do you know ".." means the parent folder of the current folder?

Add a breakpoint at the line of "saveas()", run your code and when it is paused, go to Command Window and see if you can successfully run this. If not, figure out the problem.

cd('../data_analysis/CL_over_CD_plot')