I have the following simple code, and I tried to use one of the indices from the .txt file. The index that I want is at (4,1) while the size of my matrix in the .txt file is (8,4). When I run the code, MATLAB give me the following error;
Attempted to access q(4,1); index out of
bounds because size(q)=[1,601]
Can someone help me understand why I receive the error and how to fix it?
Here is the code:
q = fileread('sv11edit.txt');
toe = q(4,1)
The answer will depend on the format of the file sv11edit.txt. However, fileread returns a string of characters. In this case, it gives you a string that is 601 characters long. You receive an error because you assume that q is 8 by 4, but this is not the case.
Check what is being stored in q before you try anything like the second line of your code. The function load may be a better alternative to fileread.
Related
I have a text file with numbers that looks like this:
a.txt
0.001240242769
-0.000829468827
-0.0001689229831
0.0008228798977
-3.86881172e-05
in a MATLAB I used to be able to use
x_in = importdata('a.txt');
and x_in was in fact a vector of 5 double numbers.
I don't know what I changed yesterday but all of a sudden when I use the same function it downloads as char
x_in='0.001240242769
-0.000829468827
-0.0001689229831
0.0008228798977
-3.86881172e-05'
What did I change and how can I fix it back?
The likely cause is that the text file has something that is not recognized as number or delimiter. I would suggest to use load as following:
x_in = load('a.txt', '-ascii');
I have an application that translates the .csv files I currently have into the correct format I need. But, the files I that I do have seem to have '"' double quotes around them, as seen in this image, which will not work with the program. As a result, I'm using this command to remove them:
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
end
end
I'm not entirely sure that this works though, as it spits this back at me as it runs:
Warning: Inputs must be character arrays or cell arrays of strings.
When I open the file in matlab, it seems to only have the single quotes around it, which is normal for any other file. However, when I open it in notepad++, it seems to have '"' double quotes around everything. Is there a way to remove these double quotes in any other way? My code doesn't seem to do anything as seen here:
After using xlswrite to write the replacement cell-array to a .csv file, one appears corrupted. Any idea why?
So, my questions are:
Is there any way to remove the quotes in a more efficient manner or without rewriting to a csv?
and
What exactly is causing the corruption in the xlswrite function? The variable replacement seems perfectly normal.
Thanks in advance!
Regarding the "corrupted" file. That's not a corrupted file, that's an xls file (not xlsx). You could verify this opening the text file in a hex editor to compare the signature. This happens when you chose no file extension or ask excel to write a file which can't be encoded into csv. I assume it's some character which causes the problems, try to isolate the critical line writing only parts of the cell.
Regarding your warning, not having the actual input I could only guess what's wrong. Again, I can only give some advices to debug the problem yourself. Run this code:
lastwarn('')
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
if ~isempty(lastwarn)
keyboard
lastwarn('')
end
end
end
This will launch the debugger when a warning is raised, allowing you to check the content of current{m,n}
It is mentionned in the documentation of strrep that :
The strrep function does not find empty strings for replacement. That is, when origStr and oldSubstr both contain the empty string (''), strrep does not replace '' with the contents of newSubstr.
You can use this user function substr like this :
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = substr(current{m,n}, 2, -1);
end
end
Please use xlswrite function like this :
[status,message] = xlswrite(___)
and check the status if it is zero, that means the function did not succeed and an error message is generated in message as string.
I want to import the large data set (multiple column) by using the following code. I want to get all in a single column instead only one row (multi column). So i did transpose operation but it still doesn't work appropriately.
clc
clear all
close all
dataX_Real = fopen('dataX_Real_in.txt');dataX_Real=dataX_Real';
I will really appreciate your support and suggestions. Thank You
The sample files can be found using the following link.
When using fopen, all you are doing is opening up the file. You aren't reading in the data. What is returned from fopen is actually a file pointer that gives you access to the contents of the file. It doesn't actually read in the contents itself. You would need to use things like fread or fscanf to read in the content from the text data.
However, I would recommend you use dlmread instead, as this doesn't require a fopen call to open your file. This will open up the file, read the contents and store it into a variable in one function call:
dataX_Real = dlmread('dataX_Real_in.txt');
By doing the above and using your text file, I get 44825 elements. Here are the first 10 entries of your data:
>> format long;
>> dataX_Real(1:10)
ans =
Columns 1 through 4
-0.307224970000000 0.135961950000000 -1.072544100000000 0.114566020000000
Columns 5 through 8
0.499754310000000 -0.340369000000000 0.470609910000000 1.107567700000000
Columns 9 through 10
-0.295783020000000 -0.089266816000000
Seems to match up with what we see in your text file! However, you said you wanted it as a single column. This by default reads the values in on a row basis, so here you can certainly transpose:
dataX_Real = dataX_Real.';
Displaying the first 10 elements, we get:
>> dataX_Real = dataX_Real.';
>> dataX_Real(1:10)
ans =
-0.307224970000000
0.135961950000000
-1.072544100000000
0.114566020000000
0.499754310000000
-0.340369000000000
0.470609910000000
1.107567700000000
-0.295783020000000
-0.089266816000000
I have a csv file with both numbers and letters that I want to read. The file also has headers(first row) but I can read them separately so that's not a concern.
What I can't solve is the fact that the file has multiple data types and that I only want to read a portion(since the file is very large), say the first 5000 rows.
I've tried xlsread with three outputs but I get the following error : "??? Error: Object returned error code: 0x800A03EC". I've also tried textscan but if I understood correctly you've to type the variable types as an input and that's not very practical for me since I have a large amount of columns. I hope this is not a duplicate but I've read other solutions and I could not apply them to my problem.
Is there a way to do this?
Thank you in advance
To test the problem i created a small test.csv file.
It contains the following lines:
header1;header2;header3
a;1;xx
b;2;yy
c;3;zz
d;4;xxx
e;5;yyy
I use the following code to read the data:
range = 'A2:C3'
[num, text, both] = xlsread('test.csv', 1, range)
Output of the both variable, that contains the text and numbers, is as expected:
both =
'a' [1] 'xx'
'b' [2] 'yy'
I am writing a program to plot graphs in a loop and I want to save each graph that comes out as a .jpg file with a variation of the file name. Here is my code for saving the graphs:
filename = strcat('WI_Pollutants_', D(i,6), '_200706_O3');
saveas(gcf, filename, 'jpg');
The saved file should come out as the following with D(i,6) changing each iteration of the loop.
WI_Pollutants_003-0010_200706_O3.jpg
However, I'm running an error: (Maybe it has to due with saveas wanting a string only?)
Error using saveas (line 81)
Invalid filename.
saveas only accepts characters as the filename. But when filename was created, strcat made it a cell array. Therefore, the filename needs to be converted to a character array.
filename = char(strcat('WI_Pollutants_', D(i,6), '_200706_O3'));
saveas(gcf, filename, 'jpg');
This solves the problem.
I think your D{i,6} is ending up wrapped up as an array, from this line:
D{i,6} = [num2str(D{i,6}) '-' num2str(D{i,7})];
To solve this, just removing the []'s
D{i,6} = num2str(D{i,6}) '-' num2str(D{i,7});
I think what happened is your D{i,6}=['someString'], and concatinating added in the []'s that werent' desired.
As a check, if something like this happens again, just fprintf(filename) right before use, and look at what comes out. I suspect you'll find the issue there. You can always remove the print statement later on.