the for loop is only giving me the last value

Hello guys, the for loop only gives me the last value of the .csv file. Some people have the same issue as mine seam. Most posts recommend adding a zero vector. I added the zero vector, but the problem is still remaining.

Data_table = readtable('20170401damlbmp_zone.csv')
Data_20170401 = readmatrix('20170401damlbmp_zone.csv')
% take the N.Y.K and North inromation from the loaded files
North_20170401 = zeros(360,6);
N_Y_K_20170401 = zeros(360,6);
for i = 10 :15 : 360
    %for j = 1:1:24
        disp( Data_20170401(i,3))
        N_Y_K_20170401(i,1)=  Data_20170401(i,3);
        x= i+1;
        North_20170401(i,1) = Data_20170401(x,3);
  %  end
end 

[the cyclist]

Can you upload the data, using the paperclip icon in the INSERT section of the toolbar?

Answer 1

[Star Strider]

There are likely a lot of zeros in the vectors because of the way ‘i’ is defined.

The loop is likely not necessary anyway.

Try something like this —

i = 10 : 15 : 360;
N_Y_K_20170401 =  Data_20170401(i,3);
North_20170401 = Data_20170401(i+1,3);

.

[Othman Alkandri]

thank you, I tried it and it dive one value instead of a vector

[Star Strider]

Something is plainly wrong with the variables read from the files, then. I suspect that there are actually very few of them, possibly less than 25.

[the cyclist]

Reiterating my comment above, if you post the actual data it will be easier to diagnose the problem.

[Othman Alkandri]

@the cyclist I attached the .CSV file

[Star Strider]

The ‘Time Stamp’ variable is a bit ambiguous and needs clarification, however my code works with this file, producing 2 (24x1) vectors (with a slight change in the subscripting, using curly braces {} instead of parentheses () to return a double array instead of a table) —

Data_20170401 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/867505/20170401damlbmp_zone.csv', 'VariableNamingRule','preserve')

Warning: The DATETIME data was created using format 'MM/dd/uuuu HH:mm' but also matched 'dd/MM/uuuu HH:mm'.
To avoid ambiguity, supply a datetime format using SETVAROPTS, e.g.
opts = setvaropts(opts,varname,'InputFormat','MM/dd/uuuu HH:mm');

Data_20170401 = 360×6 table
       Time Stamp          Name       PTID     LBMP ($/MWHr)    Marginal Cost Losses ($/MWHr)    Marginal Cost Congestion ($/MWHr)
    ________________    __________    _____    _____________    _____________________________    _________________________________

    04/01/2017 00:00    {'CAPITL'}    61757        42.86                     0.49                             -31.81              
    04/01/2017 00:00    {'CENTRL'}    61754        12.27                     0.14                              -1.56              
    04/01/2017 00:00    {'DUNWOD'}    61760        34.44                     0.98                              -22.9              
    04/01/2017 00:00    {'GENESE'}    61753        11.68                    -0.08                              -1.19              
    04/01/2017 00:00    {'H Q'   }    61844        10.26                    -0.31                                  0              
    04/01/2017 00:00    {'HUD VL'}    61758        33.04                     0.88                              -21.6              
    04/01/2017 00:00    {'LONGIL'}    61762         34.9                     1.44                              -22.9              
    04/01/2017 00:00    {'MHK VL'}    61756        13.07                     0.15                              -2.36              
    04/01/2017 00:00    {'MILLWD'}    61759        34.57                     0.97                             -23.03              
    04/01/2017 00:00    {'N.Y.C.'}    61761        34.48                     1.09                             -22.83              
    04/01/2017 00:00    {'NORTH' }    61755        10.15                    -0.41                                  0              
    04/01/2017 00:00    {'NPX'   }    61845        38.27                     0.75                             -26.95              
    04/01/2017 00:00    {'O H'   }    61846        12.04                     -0.1                              -1.57              
    04/01/2017 00:00    {'PJM'   }    61847        21.21                     0.37                             -10.28              
    04/01/2017 00:00    {'WEST'  }    61752        12.24                     0.15                              -1.53              
    04/01/2017 01:00    {'CAPITL'}    61757        39.35                      0.5                             -28.28              

i = 10 : 15 : 360;
N_Y_K_20170401 =  Data_20170401{i,3}

N_Y_K_20170401 = 24×1

61761 61761 61761 61761 61761 61761 61761 61761 61761 61761

North_20170401 = Data_20170401{i+1,3}

North_20170401 = 24×1

61755 61755 61755 61755 61755 61755 61755 61755 61755 61755

PTIDu = unique(Data_20170401{:,3});                         % Information: Inique Values
idx61755 = find(Data_20170401{:,3} == 61755)                % Information: Find Indices

idx61755 = 24×1

11 26 41 56 71 86 101 116 131 146

D61755 = diff(idx61755)                                     % Information: Find Intervals

D61755 = 23×1

15 15 15 15 15 15 15 15 15 15

idx61761 = find(Data_20170401{:,3} == 61761)                % Information: Find Indices

idx61761 = 24×1

10 25 40 55 70 85 100 115 130 145

D61761 = diff(idx61761)                                     % Information: Find Intervals

D61761 = 23×1

15 15 15 15 15 15 15 15 15 15

Further investigation reveals that the ‘PTID’ values repeat periodically (every 15 indices) so the same number always presents in the vectors.

So the loop is not necesary.

Has the problem been solved?

.

[Othman Alkandri]

@Star Strider

Thank you a lot

[Star Strider]

As always, my pleasure!

.