Dynamic matrix with loop

I have a probably simple question I have not been able to solve. Yes, I've gone through the questions and the answers didn't seem to help me.

Here is the code:

clc
Feb=textread('/Users/treybuechler/Desktop/Irradiance_Data/Feb2013/data.txt');

[Time,x]=size(Feb);

second=1;

min=60*second;

hour=60*min;

day=24*hour;

day=int64(day);

num_days=(Time/day);

k=floor(num_days);

k=int64(k);

Day=zeros(1,day);

for i=0:k-1

     l=(i)*day+1;
     m=(i+1)*day;
     Day(:,i+1)=Feb(1:m);

end

What I am trying to do is I have a text file that contains a string of numbers, data taken at every second. I want to read the data in (this works) I then get this array:

Feb           1048327x1

Now, since I don't know how much data is in each text file, I use the equations to get the number of seconds in a day..and from the data read in, find out how many days there are...Then I want to use that loop to create a matrix of data that has either a column for each day or a row for each day, preferably a column. So, I'm just taking the 'Feb' array and taking chunks and placing them in the expanding matrix Day. I have tried several different things suggested on different posts, but nothing has worked. Here is the error I get

??? Subscripted assignment dimension mismatch.

Error in ==> irradiance_data at 23
   Day(:,i+1)=Feb(1:m);

and here is the list of variables if that helps at all

Name                Size                 Bytes  Class     Attributes

Day                 1x86400             691200  double              
Feb           1048327x1                8386616  double              
Time                1x1                      8  double              
day                 1x1                      8  int64               
hour                1x1                      8  double              
i                   1x1                      8  int64               
k                   1x1                      8  int64               
l                   1x1                      8  int64               
m                   1x1                      8  int64               
min                 1x1                      8  double              
num_days            1x1                      8  int64               
second              1x1                      8  double              
x                   1x1                      8  double

That should be all the information anyone needs. I didn't want to resort to posting a question, but I've run through all the things I could find.

Thank you very much.

Answer 1

[Walter Roberson]

Change

Day=zeros(1,day);

to

Day = zeros(day, 1);

Answer 2

[Trey]

Thanks, for the reply, I've tried that before, tried it again and receive the same error Regards.

Answer 3

[Jan]

At first I suggest to use the debugger to check the dimensions of the variables in the crashing line. Type this in the command window:

dbstop if error

Then start your program again. It stops when the error occurs. Then type this in the command line:

size(Day(:,i+1))
size(Feb(1:m))

Do the sizes match?

I suggest to simplify the function to e.g.:

Feb   = textread('/Users/treybuechler/Desktop/Irradiance_Data/Feb2013/data.txt');
nTime = size(Feb, 1);
nDay  = round(nTime / 86400);
Day   = reshape(Feb(1:nDay * 86400), 86400, nDay);

Remark: The conversions to int64 are not useful in your code.

[Trey]

I did this and this was the result:

K>> size(Day(:,i+1)) ??? Index exceeds matrix dimensions.

K>> size(Feb(1:m))

ans =

      172800           1

However, using the code you suggested it worked perfectly. THank you very much. I originally used the int conversion because i was getting errors for the contents being of type double..

So, The next question is how to get this to plot against time=86400?