I'm unable to load an entire data set from CSV in Matlab. I'm new to Matlab so if the solution is trivial I apologize in advance.
The CSV is of dimension [2885 x 7].
I'm using data = importdata(filename, ','); which, according to the documentation is the correct usage.
However, the result of data of size [1332 x 7].
I've checked the CSV and there are no anomalies. Any ideas?
Related
I have a sequence of data files(".tab" files) with more than 11100 rows and 236 columns. Data begins from 297th line in one file and from 299th line in another file. How can I read the data from 297th row of each file in MATLAB R2014a?
I am not quite sure, bu it seems that a typical machine's memory can handle such a file size. In that case, you can use textscan or textread MATLAB built-in functions.
Nonetheless, if you really cannot import your data into MATLAB environment, set HeaderLines argument of textscan to the line of interest. A simple example can be found in MATLAB documentations, or:
SelectedData = textscan(ID,formatSpec,'HeaderLines',296); % Ignore 296 first lines of the data
First of all, I strongly recommend to review the MATLAB documentation. Assuming you have several files in hand (stored in fileNames:
for i = 1:numel(fileNames)
ID = fopen(fileNames{i});
formatSpec = '%s %[^\n]'; % Modify this based on your file structure
SelectedData{i} = textscan(ID,formatSpec,'HeaderLines',296);
fclose(ID);
end
SelectedData is a cell string containing all your data extracted from corresponding data (fileNames)
I have large .bin files (10GB 60GB) that I want to import to MATLAB; each binary file represents the output of two sensors, thus there are too columns of data. Here is a more manageable sized example of my data.
You will notice that there is a .txt version of the data; I need to upload the .bin files directly to MATLAB, I can't use the .txt version because it takes hours to convert with larger files.
The problem I have is that the .bin file has header information that I can't seem to interpret properly, and thus I cannot extract the data in MATLAB every time I try I seem to get gibberish values.
This is all the information I have about the binary header:
Loading Labview Binary Data into Matlab
LabVIEW Data Logger: Binary Header File Format
Any help/advice would be much appreciated I have been trying to solve this problem for days now.
P.S. Someone has already written a function to solve this problem but it does not seem to work with my binary data (could be something to do with the dimensions/size of my data): http://www.mathworks.co.uk/matlabcentral/fileexchange/27195-load-labview-binary-data
Below is the code that I am using to import my data, I believe that that d1 and d2 are the dimensions of my binary data. D2 is probably incorrect for the example file in the dropbox because it has been truncated.
The problem I have is that the code extracts my data and I know it is correct because I can check it with the .txt file (also in the drop box) however there are seaming random bad values between the good data points. These bad values result from the following strings following strings: "NI_ChannelName", "Sensor A", "Sensor B", "NI_UnitDescription", and "Volts" scatted throughout the binary file.
clear all
clc
fname = 'RTL5_57.bin';
fid = fopen(fname,'r','ieee-be');
d1 = fread(fid,4);
trash=fread(fid,2,'double');
d2 = fread(fid,4);
trash=fread(fid,1,'double');
data=fread(fid,'double');
I suppose you will need to change the data-format. See Matlab help.
https://decibel.ni.com/content/docs/DOC-39038
Scope:
1) Write a binary file in matlab and read into labview. 2) Write a binary file in labview and read into matlab.
Background:
IMPORTANT:
You must know (3) things about the binary data in the file before you can read the data:
1) what binary format (precision) was used to store the data
2) the exact number of values in the file to read.
3) Endianness
There is no row or column in binary files. Think of a long row/or a long column that needs to be mapped to a 2D array.
Resources on data in binary format.
http://cse.unl.edu/~sincovec/Matlab/Lesson%2024/Binary/CS211%20Lesson%2024%20-%20Binary%20File%20Input-Output.htm
I have a data file having 50 2-D data points written in Notepad. I want to use it in clustering algorithm to cluster these 50 points. How can I import this file? Is there any other way to use it in program?
You can save the data as a .csv file or you can save it to an excel spreadsheet and use xlsread(). See here for more info: http://www.mathworks.com/help/techdoc/ref/xlsread.html
For the .csv case, this post should prove helpful: Fastest way to import CSV files in MATLAB
Imagine you had the following data:
X = [randn(100,2)-1 ; randn(100,2)];
save data.mat X
Then its as simple as doing:
%# load data from MAT-file
load data.mat
%# cluster into K=2 clusters
C = kmeans(X,2);
%# show cluster assignment
gscatter(X(:,1), X(:,2), C)
It depends how you have formatted the data file. You say it is saved on notepad but that is not too helpful. Depending on what you have used as the data delimiter you can import the datafile into an array using the dlmread function. For example if your file is called filename.dat and have used a ; character to separate each data item within this file you could read the data into a matrix A using
A = dlmread("filename.dat",';');
I would suggest reading the help documentation on the dlmread function in matlab.
I have 20 text files each containing a vector of size 180. How can I access each text file and assign the vector to a variable?
If you want to do it manually use Import Data under File (or use uiimport).
If you want to automate it use fid = fopen(filename) and then use var = textscan(fid, 'format') where format depends on how your vectors are structured. Spend some time reading doc textscan and doc fopen everything you probably need to know is in those two files. If your data is nicely structured look at doc importdata.
I am trying to load an xls file in MATLAB. The xls file contains numerical values. I have successfully loaded and plotted the file but if I change the dimensions of the file (i.e. number of rows and number of columns) there is an error:
Numeric = xlsread('Test_results_new')
??? No appropriate method or public field UsedRange for class Interface.Microsoft_Excel_12.0_Object_Library._Chart.
Please note that when I make a change in the xls file I also make changes in the MATLAB code for number of rows and columns.
Can someone help me?
I had the same problem recently after months of it continuously working, I found out it was because I had made a plot in the excel file, so (i think) when xlsread was called it was looking at the first sheet (the plot instead of the table) and obviously could not read it. You can specify which sheet to look at with xlsread, just type help xlsread and it will explain how