How to Read .dat File in Matlab + Multiband

MATLAB - Data Import

Importing information in MATLAB means loading information from an external file. The importdata office allows loading diverse data files of different formats. Information technology has the following 5 forms −

Sr.No.	Function & Description
1	A = importdata(filename) Loads data into array A from the file denoted by filename.
2	A = importdata('-pastespecial') Loads information from the system clipboard rather than from a file.
three	A = importdata(___, delimiterIn) Interprets delimiterIn as the column separator in ASCII file, filename, or the clipboard data. You can use delimiterIn with any of the input arguments in the above syntaxes.
iv	A = importdata(___, delimiterIn, headerlinesIn) Loads information from ASCII file, filename, or the clipboard, reading numeric data starting from line headerlinesIn+1.
5	[A, delimiterOut, headerlinesOut] = importdata(___) Returns the detected delimiter character for the input ASCII file in delimiterOut and the detected number of header lines in headerlinesOut, using any of the input arguments in the previous syntaxes.

Past default, Octave does not take support for importdata() role, so you will have to search and install this package to make following examples work with your Octave installation.

Example 1

Permit the states load and display an prototype file. Create a script file and type the following code in it −

filename = 'grin.jpg'; A = importdata(filename); prototype(A);

When you run the file, MATLAB displays the prototype file. Notwithstanding, you must shop it in the electric current directory.

Importing Imange Files

Example 2

In this example, nosotros import a text file and specify Delimiter and Cavalcade Header. Let us create a space-delimited ASCII file with column headers, named weeklydata.txt.

Our text file weeklydata.txt looks similar this −

SunDay  Monday  TuesDay  Midweek  Th  Fri  Sat 95.01   76.21   61.54    40.57       55.79    70.28   81.53 73.11   45.65   79.19    93.55       75.29    69.87   74.68 60.68   41.85   92.eighteen    91.69       81.32    90.38   74.51 48.sixty   82.14   73.82    41.03       0.99     67.22   93.18 89.13   44.47   57.63    89.36       thirteen.89    19.88   46.60

Create a script file and type the following code in it −

filename = 'weeklydata.txt'; delimiterIn = ' '; headerlinesIn = 1; A = importdata(filename,delimiterIn,headerlinesIn);  % View data for chiliad = [i:seven]    disp(A.colheaders{1, thou})    disp(A.data(:, 1000))    disp(' ') stop

When you run the file, information technology displays the post-obit upshot −

SunDay    95.0100    73.1100    sixty.6800    48.6000    89.1300   MonDay    76.2100    45.6500    41.8500    82.1400    44.4700   TuesDay    61.5400    79.1900    92.1800    73.8200    57.6300  Wednesday    40.5700    93.5500    91.6900    41.0300    89.3600   ThursDay    55.7900    75.2900    81.3200    0.9900    13.8900   FriDay    seventy.2800    69.8700    90.3800    67.2200    19.8800  Sabbatum    81.5300    74.6800    74.5100    93.1800    46.6000

Example 3

In this example, let u.s. import data from clipboard.

Copy the following lines to the clipboard −

Mathematics is simple

Create a script file and blazon the following code −

A = importdata('-pastespecial')

When y'all run the file, information technology displays the following upshot −

A =     'Mathematics is simple'

Depression-Level File I/O

The importdata function is a loftier-level function. The depression-level file I/O functions in MATLAB allow the most control over reading or writing data to a file. However, these functions need more detailed information about your file to work efficiently.

MATLAB provides the following functions for read and write operations at the byte or grapheme level −

Role	Description
fclose	Shut one or all open files
feof	Test for stop-of-file
ferror	Information about file I/O errors
fgetl	Read line from file, removing newline characters
fgets	Read line from file, keeping newline characters
fopen	Open file, or obtain information about open up files
fprintf	Write data to text file
fread	Read information from binary file
frewind	Move file position indicator to beginning of open up file
fscanf	Read data from text file
fseek	Movement to specified position in file
ftell	Position in open file
fwrite	Write data to binary file

Import Text Information Files with Low-Level I/O

MATLAB provides the following functions for low-level import of text data files −

The fscanf role reads formatted data in a text or ASCII file.
The fgetl and fgets functions read one line of a file at a time, where a newline grapheme separates each line.
The fread role reads a stream of data at the byte or bit level.

Case

We have a text data file 'myfile.txt' saved in our working directory. The file stores rainfall data for three months; June, July and August for the twelvemonth 2012.

The data in myfile.txt contains repeated sets of time, calendar month and rainfall measurements at 5 places. The header information stores the number of months M; so we have M sets of measurements.

The file looks like this −

Rainfall Data Months: June, July, August   Yard = 3 12:00:00 June-2012 17.21  28.52  39.78  sixteen.55 23.67 xix.fifteen  0.35   17.57  NaN   12.01 17.92  28.49  17.forty  17.06 11.09 nine.59   9.33   NaN    0.31  0.23  x.46  thirteen.17  NaN    14.89 19.33 20.97  19.l  17.65  14.45 xiv.00 18.23  10.34  17.95  16.46 nineteen.34 09:10:02 July-2012 12.76  16.94  14.38  11.86 xvi.89 xx.46  23.17  NaN    24.89 19.33 30.97  49.l  47.65  24.45 34.00 18.23  30.34  27.95  16.46 19.34 xxx.46  33.17  NaN    34.89  29.33 30.97  49.50  47.65  24.45 34.00 28.67  30.34  27.95  36.46 29.34 fifteen:03:40 August-2012 17.09  16.55  19.59  17.25 19.22 17.54  11.45  13.48  22.55 24.01 NaN    21.19  25.85  25.05 27.21 26.79  24.98  12.23  16.99 eighteen.67 17.54  eleven.45  xiii.48  22.55 24.01 NaN    21.19  25.85  25.05 27.21 26.79  24.98  12.23  sixteen.99 18.67

Nosotros will import data from this file and display this data. Accept the post-obit steps −

Open the file with fopen function and get the file identifier.
Depict the data in the file with format specifiers, such as '%southward' for a string, '%d' for an integer, or '%f' for a floating-point number.
To skip literal characters in the file, include them in the format description. To skip a data field, employ an asterisk ('*') in the specifier.

For case, to read the headers and return the single value for M, we write −
```
1000 = fscanf(fid, '%*south %*southward\n%*southward %*south %*s %*due south\nM=%d\n\northward', 1);            
```
By default, fscanf reads information co-ordinate to our format clarification until it does not discover any match for the information, or it reaches the end of the file. Hither we will apply for loop for reading 3 sets of information and each time, information technology will read 7 rows and v columns.
We will create a structure named mydata in the workspace to shop data read from the file. This construction has iii fields - time, month, and raindata assortment.

Create a script file and type the following code in it −

filename = '/data/myfile.txt'; rows = 7; cols = 5;   % open the file fid = fopen(filename);   % read the file headers, find K (number of months) One thousand = fscanf(fid, '%*southward %*s\n%*s %*south %*s %*southward\nM=%d\north\northward', one);   % read each set of measurements for due north = 1:G    mydata(n).time = fscanf(fid, '%s', 1);    mydata(n).month = fscanf(fid, '%s', 1);      % fscanf fills the array in column order,    % so transpose the results    mydata(due north).raindata  = ...       fscanf(fid, '%f', [rows, cols]); terminate for n = 1:Chiliad    disp(mydata(n).time), disp(mydata(n).month)    disp(mydata(n).raindata) terminate   % close the file fclose(fid);

When y'all run the file, information technology displays the post-obit event −

12:00:00 June-2012    17.2100   17.5700   11.0900   xiii.1700   14.4500    28.5200       NaN    9.5900       NaN   xiv.0000    39.7800   12.0100    9.3300   14.8900   18.2300    16.5500   17.9200       NaN   xix.3300   10.3400    23.6700   28.4900    0.3100   20.9700   17.9500    19.1500   17.4000    0.2300   nineteen.5000   xvi.4600    0.3500   17.0600   x.4600   17.6500   19.3400  09:ten:02 July-2012    12.7600       NaN   34.0000   33.1700   24.4500    xvi.9400   24.8900   18.2300       NaN   34.0000    fourteen.3800   nineteen.3300   xxx.3400   34.8900   28.6700    eleven.8600   30.9700   27.9500   29.3300   30.3400    xvi.8900   49.5000   16.4600   30.9700   27.9500    20.4600   47.6500   19.3400   49.5000   36.4600    23.1700   24.4500   30.4600   47.6500   29.3400  xv:03:40 Baronial-2012    17.0900   13.4800   27.2100   eleven.4500   25.0500    sixteen.5500   22.5500   26.7900   xiii.4800   27.2100    nineteen.5900   24.0100   24.9800   22.5500   26.7900    17.2500       NaN   12.2300   24.0100   24.9800    xix.2200   21.1900   16.9900       NaN   12.2300    17.5400   25.8500   18.6700   21.1900   16.9900    11.4500   25.0500   17.5400   25.8500   18.6700