Reading excel with matlab

xlsread

Description

values = {1, 2, 3 ; 4, 5, 'x' ; 7, 8, 9};
headers = {'First','Second','Third'};
xlswrite('myExample.xlsx',[headers; values]);

   First    Second    Third
       1         2        3
       4         5    x    
       7         8        9

filename = 'myExample.xlsx';
A = xlsread(filename)

filename = 'myExample.xlsx';
sheet = 1;
xlRange = 'B2:C3';

subsetA = xlsread(filename,sheet,xlRange)

filename = 'myExample.xlsx';

columnB = xlsread(filename,'B:B')

[num,txt,raw] = xlsread('myExample.xlsx')

num =
     1     2     3
     4     5   NaN
     7     8     9

txt = 
    'First'    'Second'    'Third'
    ''         ''          ''     
    ''         ''          'x'    

raw = 
    'First'    'Second'    'Third'
    [    1]    [     2]    [    3]
    [    4]    [     5]    'x'    
    [    7]    [     8]    [    9]

function [Data] = setMinMax(Data)

minval = 0.2; 
maxval = 0.8;
 
for k = 1:Data.Count
  v = Data.Value{k};
  if v > maxval
    Data.Value{k} = maxval;
  elseif v < minval
    Data.Value{k} = minval;
  end
end

A = rand(5);
xlswrite('myExample.xlsx',A,'MyData')

trim = xlsread('myExample.xlsx','MyData','','',@setMinMax);

function [Data,indices] = setMinMax(Data)

minval = 0.2; 
maxval = 0.8;
indices = [];
 
for k = 1:Data.Count
  v = Data.Value{k};
  if v > maxval
    Data.Value{k} = maxval;
    indices = [indices k];
  elseif v < minval
    Data.Value{k} = minval;
    indices = [indices k];
  end  
end

[trim,txt,raw,idx] = xlsread('myExample.xlsx',...
    'MyData','','',@setMinMax);

M = xlsread(filename)

T = readtable(filename)

M = readmatrix(filename)

[~,~,C] = xlsread(filename)

T = readtable(filename)

C = readcell(filename)

M = xlsread(filename,sheet,range)

T = readtable(filename,'Sheet',sheet,'Range',range)

M = readmatrix(filename,'Sheet',sheet,'Range',range)

[~,~,C] = xlsread(filename,sheet,range)

T = readtable(filename,'Sheet',sheet,'Range',range)

C = readcell(filename,'Sheet',sheet,'Range',range)

Описание

values = {1, 2, 3 ; 4, 5, 'x' ; 7, 8, 9};
headers = {'First','Second','Third'};
xlswrite('myExample.xlsx',[headers; values]);

   First    Second    Third
       1         2        3
       4         5    x    
       7         8        9

filename = 'myExample.xlsx';
A = xlsread(filename)

filename = 'myExample.xlsx';
sheet = 1;
xlRange = 'B2:C3';

subsetA = xlsread(filename,sheet,xlRange)

filename = 'myExample.xlsx';

columnB = xlsread(filename,'B:B')

[num,txt,raw] = xlsread('myExample.xlsx')

num =
     1     2     3
     4     5   NaN
     7     8     9

txt = 
    'First'    'Second'    'Third'
    ''         ''          ''     
    ''         ''          'x'    

raw = 
    'First'    'Second'    'Third'
    [    1]    [     2]    [    3]
    [    4]    [     5]    'x'    
    [    7]    [     8]    [    9]

function [Data] = setMinMax(Data)

minval = 0.2; 
maxval = 0.8;
 
for k = 1:Data.Count
  v = Data.Value{k};
  if v > maxval
    Data.Value{k} = maxval;
  elseif v < minval
    Data.Value{k} = minval;
  end
end

A = rand(5);
xlswrite('myExample.xlsx',A,'MyData')

trim = xlsread('myExample.xlsx','MyData','','',@setMinMax);

function [Data,indices] = setMinMax(Data)

minval = 0.2; 
maxval = 0.8;
indices = [];
 
for k = 1:Data.Count
  v = Data.Value{k};
  if v > maxval
    Data.Value{k} = maxval;
    indices = [indices k];
  elseif v < minval
    Data.Value{k} = minval;
    indices = [indices k];
  end  
end

[trim,txt,raw,idx] = xlsread('myExample.xlsx',...
    'MyData','','',@setMinMax);

M = xlsread(filename)

T = readtable(filename)

M = readmatrix(filename)

[~,~,C] = xlsread(filename)

T = readtable(filename)

C = readcell(filename)

M = xlsread(filename,sheet,range)

T = readtable(filename,'Sheet',sheet,'Range',range)

M = readmatrix(filename,'Sheet',sheet,'Range',range)

[~,~,C] = xlsread(filename,sheet,range)

T = readtable(filename,'Sheet',sheet,'Range',range)

C = readcell(filename,'Sheet',sheet,'Range',range)

Представлено до R2006a

This article is a quick tutorial on using the xlsread MATLAB command to import data from an Excel file into MATLAB. Specifically, you’ll learn to:

• Extract data from Excel in MATLAB
• Remove irrelevant content from your extract
• Import data from a specific sheet
• Select the Excel file to read
• Extract different formats

How to Extract Data from Excel in MATLAB

Xlsread Basic Syntax

Here’s the basic syntax to import data from Excel into MATLAB:

[numbers text textAndNumbers] = xlsread(excelFileName)

• numbers: numbers contained in your Excel file.
• text: text contained in your Excel file.
• textAndNumbers: text and numbers contained in your Excel file.

Xlsread MATLAB Example

First, let’s look at some details about how this works through an actual example. Let’s say I have the following Excel file named “excelFile.xlsx:”

Then, applying the previous basic syntax to read it, we get:

excelFileName = 'excelFile.xlsx';
[numbers text textAndNumbers] = xlsread(excelFileName);

So, let’s examine the outputs of the xlsread MATLAB command:

As you can see, the three outputs are not of the same data type:

• “numbers” is an array: this means that you can access the content of an element using parentheses: numbers(i)
• “text” is a cell array: this means that you can access the content of a cell using braces: text{i}
• “numbersAndText” is a cell array: this means that you can access the content of a cell using braces: numbersAndText{i}

Remove Irrelevant Content from Your Extract

• Notice that for the “numbers” variable, the first and last rows have been removed, and the text has been replaced by “NaN” value. You can get rid of the “NaN” values with the following:
  

  numbers = numbers(~isnan(numbers)); % delete numbers that are not "NaN"

  The “numbers” variable then becomes:
  

• The numbers contained in the “text” variable have been replaced by empty cells. You can get rid of the empty cells with the following:
  

  text = text(~cellfun('isempty', text)); % delete empty cells

  The “text” variable then becomes:
  

Import Data from a Specific Sheet

What If the Content Is in Another Sheet?

Let’s use the previous Excel file “excelFile.xlsx” with the content on a sheet named “Sheet1” (which is the default name of a sheet if you create an Excel file).
Moreover, if you add a sheet to the Excel file, the name of the sheet will be “Sheet2.” So, let’s do that and move the first sheet (with the previous content) to the right of the second sheet and save the file:

Then, we’ll apply the xlsread MATLAB command as we did previously:

excelFileName = 'excelFile.xlsx';
[numbers text textAndNumbers] = xlsread(excelFileName);

By default, xlsread will read the sheet located at the very left of the Excel file, namely “Sheet2.”

Since “Sheet2” is empty, it makes sense that the extracted content is empty. So, how do you read “Sheet1”?

Finding a Sheet

First, there are two ways to specify the sheet to read using the xlsread MATLAB command:

1. Using the number of the sheet:
   

   [numbers text textAndNumbers] = xlsread(excelFileName, sheetNumber);

   The number of the sheet is “2” here because we want to read the second sheet (counting from the left). So, giving the “sheetNumber” variable the value “1” is equivalent to not using the second argument of the xlsread MATLAB command. Here’s how to extract the desired sheet:

   sheetNumber = 2; % second sheet counting from the left
   excelFileName  = 'excelFile.xlsx';
   [numbers text textAndNumbers] = xlsread(excelFileName, sheetNumber);

2. Using the name of the sheet:
   

   [numbers text textAndNumbers] = xlsread(excelFileName, sheetName);

   The sheet name in that example is “Sheet1,” so you can use it as the second argument if you want to extract the second sheet:

   sheetName = 'Sheet1';
   excelFileName  = 'excelFile.xlsx';
   [numbers text textAndNumbers] = xlsread(excelFileName, sheetName);

In both cases, if the sheet number or the sheet name you’re referring to doesn’t exist, you’ll get the following error:

Specific Problems and Solutions

Ask the User to Select an Excel File

Using the uigetfile MATLAB command, you can ask the user to find and select the desired excel file to be read:

[fileName, pathName] = uigetfile({'*.xlsx';'*.xls'}, 'Choose an Excel file');

You can then use the “fileName” and the “pathName” (respectively the name of the selected file and its location) to read your Excel file.
There are 2 ways of doing that:

• Moving to the file’s location:
  

  [fileName, pathName] = uigetfile({'*.xlsx';'*.xls'}, 'Choose an Excel file');
  currentFolder = pwd; % save the current location
  cd(pathName)
  [numbers text textAndNumbers] = xlsread(fileName)
  cd(currentFolder);

  We use the pwd MATLAB command to save the current location from before, move to the Excel file’s location, perform the extraction, and move back to the initial location.

• Specifying the location:
  

  [fileName, pathName] = uigetfile({'*.xlsx';'*.xls'}, 'Choose an Excel file');
  fullFileExcelFile = fullfile(pathName, fileName); % create the path to the Excel file
  [numbers text textAndNumbers] = xlsread(fullFileExcelFile);

  fullfile creates the path by adding ‘/’ or ‘’ between the file name and the path name (you could do it yourself with something like [pathName ‘/’ fileName], but this can be a little bit trickier depending on whether you use a UNIX or Windows platform).

Be Careful About the Format of the Cells You’re Extracting

First, if the numbers contained in your Excel file are formatted as strings, you’ll get a cell array when extracting. For example, by adding a single quotation mark to the left of every number in the Excel file “excelFile.xlsx” that we’ve used previously, we are formatting them as strings:And if we import the data from the Excel file now, we get:

Since the numbers have been formatted as strings in the Excel file, there are no numbers anymore, the “numbers” variable is empty and the “text” and “textAndNumbers” variables have become identical.

The Empty Cell Issue

If you have empty cells in your Excel file before the first row, the xlsread MATLAB command will get rid of them. This is a problem if you want to write the content back to the Excel file (e.g. to modify a value) because you won’t be able to know where to write it.

Unfortunately, there is no easy way to get that information using xlsread. If you have this issue, you can refer to this article for a workaround: https://realtechnologytools.com/matlab-row-number/

Key takeaways:

• To read an Excel file, use:
  

  [numbers text textAndNumbers] = xlsread(excelFileName);

  • numbers: array of the numbers in the file, access an element using numbers(i)
  • text: cell array of the text in the file, access an element using text{i}
  • textAndNumbers: cell array of the text and numbers in the file, access an element using textAndNumbers{i}
• To remove irrelevant values from your extract, use:
  

  numbers = numbers(~isnan(numbers)); % delete numbers that are "NaN"
  text = text(~cellfun('isempty', text)); % delete empty cells

• To import a specific sheet in MATLAB, use:
  

  [numbers text textAndNumbers] = xlsread(excelFileName, sheetName); % use the sheet name
  [numbers text textAndNumbers] = xlsread(excelFileName, sheetNumber); % use the sheet number

• There are 2 ways to ask the user to select an Excel file and read it:
  1. By moving to the file’s location:
     

     [fileName, pathName] = uigetfile({'*.xlsx';'*.xls'}, 'Choose an Excel file');
     currentFolder = pwd; % save the current location
     cd(pathName)
     [numbers text textAndNumbers] = xlsread(fileName)
     cd(currentFolder);

  2. By specifying the location:
     

     [fileName, pathName] = uigetfile({'*.xlsx';'*.xls'}, 'Choose an Excel file');
     fullFileExcelFile = fullfile(pathName, fileName); % create the path to the Excel file
     [numbers text textAndNumbers] = xlsread(fullFileExcelFile);

• If the numbers in your Excel file are formatted as strings (e.g. using a single quotation mark at the left of a number in the Excel file), then they will be extracted in the “text” variable rather than in the “numbers” variable.

You can find more information about the xlsread MATLAB function in the MathWorks documation: https://fr.mathworks.com/help/matlab/ref/xlsread.html

If you want to learn more about the practical tips that helped me stop wasting time doing mindless work (such as working with Excel files and writing reports) I wrote a small reference book about it:

Introduction

In the previous tutorial, we learnt how to write to an Excel file from Matlab. This tutorial is a follow-up article on how to read from an Excel file from Matlab.
In this tutorial, we will learn how to read the data from an Excel file and use the data in Matlab. At the end of this tutorial, you will learn how to open an Microsoft Excel file,
read  data from a particular column into Matlab and save it in the workspace. Finally, we will plot the data and insert this plot into the same excel file.

Steps

Step 1 : The first step is to create a COM server which runs the Excel Application.

Excel = actxserver('Excel.Application'); 

This assumes that the Excel Application is installed in your system. If Excel is not installed, this statement will give an error. You can put the above statement within a try-catch block:

try
    Excel = actxserver('Excel.Application');
catch
    Excel = [];    
end 

Step 2: In this step, we will check the version of Excel.

ExcelVersion = str2num(Excel.Version);   

If the Microsoft Excel is 2007, 2010 or above, you would get ExcelVersion would be 12 or above. In such a case, you can handle all the Excel workbook files
with extensions *.xls, *.xlsx and *.xlsm. If the version is less than 12, only *.xls file would be supported. 

Step 3: In this step, we will open an Excel file “ResultFile.xls” in the current directory.

ResultFile = [pwd 'ResultFile.xls']; 
Workbook = invoke(Excel.Workbooks,'Open', ResultFile);   

Step 4: By default, the visibility of the Excel file is set to
FALSE. You can make the Excel file visible using the command:

set(Excel,'Visible',1);

Let us assume, that the Excel file looks something like this as shown in the figure. Let us develop the code to read the data from Column A and Column B in to 2 variables
iter and expResults. We will plot this data and insert this plot into the same excel file.

ResultFile = [pwd 'ResultFile.xls'];
Workbook = invoke(Excel.Workbooks,'Open', ResultFile);
resultsheet = 'ExperimentSheet';
try
    sheet = get(Excel.Worksheets,'Item', resultsheet);
    invoke(sheet, 'Activate');
catch
    % If the Excel Sheet ‘ExperimentSheet’ is not found, throw an error message
    errordlg([resultsheet 'not found']);
end

Read Experiment Column

As seen from the Excel sheet, we need to first read Column A from row 2 to row 11. First we need to select the range from A2 till A11. We use the
xlcolumn() function to convert between column
name and number for Excel representation. The xlcolumn() module can be downloaded from
here.

%% Read the Experiment Column
Location = [xlcolumn(1) '2:' xlcolumn(1) int2str(11)];
ExpIteration = get(Excel.Activesheet, 'Range',Location);
ExpIteration.Select;
if(iscell(Excel.Selection.Value))
    iter = cell2mat(Excel.Selection.Value)';
else
    iter = Excel.Selection.Value;
end
% The iter variable will now contain the data from the column A.  

Read Result Column

As seen from the Excel sheet, we need to first read Column B from row 2 to row 11. Here again, we need to select the range from B2 till B11.

%% Read the Results Column
Location = [xlcolumn(2) '2:' xlcolumn(2) int2str(11)];
ResultValue  = get(Excel.Activesheet, 'Range',Location);
ResultValue.Select;
if(iscell(Excel.Selection.Value))
    expResults = cell2mat(Excel.Selection.Value)';
else
    expResults = Excel.Selection.Value;
end
% The expResults variable will now contain the data from the column A. 

Plot the Data

Since we already have the data in the workspace, we can simply use the plot command in Matlab.

%% Plot the Data
plot(iter, expResults);
legend('Results');
xlabel('Experiment'); 
ylabel('Results');

Insert the image into Excel Sheet

In order to insert the plot into an excel sheet, we need to convert the figure object into an image.

% Convert the figure object to an image
ResultImage = 'Results.png';
print('-dpng', ResultImage); 

To place the image in the Excel sheet, we look for coordinates of the particular cell which is empty and place the image in that cell.
Let’s say, we will place the image starting from column D.

Location = [ xlcolumn(4)  int2str(2) ];
ImageRange= get(Excel.ActiveSheet,'Range',  Location);
Shapes =ExAct.Shapes;
%% Size of theimage.
imgWidth=400;
imgHeight=250;
Shapes.AddPicture([pwd'' ResultImage] ,0,1, ImageRange.Left, ImageRange.Top, imgWidth, imgHeight);   

The last step is to save the Excel file and close the Excel application:  

%Save and Close the Excel File
delete(Excel); 
invoke(Excel,'Quit');
invoke(Workbook,'Save'); 

Download Download ReadData.zip