Can I write the output of a 'summary' command of a 'table'-variable to a variable ?

>> table(A,B,C)

ans =

                A                            B                            C            
    _________________________    _________________________    _________________________

    1           2           3    4           5           6    7           8           9

>> summary(ans)

Variables:

    A: 1x3 double
        Values:
                      A_1    A_2    A_3
                      ___    ___    ___

            min       1      2      3  
            median    1      2      3  
            max       1      2      3  

    B: 1x3 double
        Values:
                      B_1    B_2    B_3
                      ___    ___    ___

            min       4      5      6  
            median    4      5      6  
            max       4      5      6  

    C: 1x3 double
        Values:
                      C_1    C_2    C_3
                      ___    ___    ___

            min       7      8      9  
            median    7      8      9  
            max       7      8      9

[Hadas]

I would also like an answer to this question as I have failed to find a way to output the table summary to a variable.

[Hadas]

Many thanks to Guillaume and Stephen Cobeldick for their excellent answers!

[Image Analyst]

Then can you go ahead and vote for them and "Accept" them.

[Luisa Liboni]

The answers were posted in 2015. I am using Matlab 2017 and it does not seem to work. I have made a local copy of the summary function and incorporated the fid into every fprinf as instructed.

By doing the hack suggested by Guilaume, I reveice the following error:

Any help?

summarynew(tab);

Unrecognized variable name 'getProperty'.

[Steven Lord]

Can you tell us a little more about how you would use that variable containing the text displayed by the summary method? Knowing that may allow us to find a way to achieve your goal without making a copy of the summary method that you would need to maintain and update with each new release as we update the summary method.

[Luisa Liboni]

I need to send information to people who do not code in Matlab so that they could see the missing information (NaT, NaN, undefined categories) and the counts of all categories, as well as the max, min and mean of numeric values. It should work as a detailed report about the table's columns. I know it would result in a long text file or csv file, however, they could process this in a word processing software/ csv processing software.

I think I manage to work this around by using the following code before calling the function summary:

diary summaryreport.txt;
summary(tab);

This prints everything that is outputed in the command window into a text file.

Anyway, It would indeed be very good if there was a way of doing this automatically with the summary method.

Answer 1

[Guillaume]

summary uses fprintf to print to the command window and has no defined output, so the only way to do this is to capture the command window output with evalc:

T = readtable('patients.dat') %demo data shipped with matlab
tablesummary = evalc('summary(T)')

[Hadas]

Many thanks!

Answer 2

[Stephen23]

As Guillaume states, the function summary uses fprintf everywhere, so it is not designed to output a variable. But we can hack the code a little...

The summary code can be re-written to do what you want. open the function and save a local copy. Do NOT edit the MATLAB file itself, and name the new file (and function) something different from summary. Then change the local copy by adding an fopen command at the start of the main function:

fid = fopen('temp_summary.txt','wt');

then replace every instance of fprintf(...) with fprintf(fid,...). You might need to pass fid to the local functions too: just add it to the input arguments, and pay attention to the editor warnings (which will tell you where this values is required). Finally at the end of the main function add fclose(fid);.

Running this function creates an Mfile which includes the complete summary text.

You can use fileread to get the entire string in one command:

str = fileread('temp_summary.txt');

Bingo: str is the summary text.

[Hadas]

Many thanks!

[Luisa Liboni]

The answers were posted in 2015. I am using Matlab 2017 and it does not seem to work. I have made a local copy of the summary function and incorporated the fid into every fprinf as instructed.

By doing the hack suggested by Guilaume, I reveice the following error:

Any help?

summarynew(tab);

Unrecognized variable name 'getProperty'.

[Stephen23]

" I have made a local copy of the summary function and incorporated the fid into every fprinf as instructed"

If you followed my answer then you would get a file containing the printed data. What happened when you tried it? Did you get a file? An error message?

Note that you will need to copy the file and give it a new name when you save it (e.g. in the current directory), and then you will need to call it by that new name. As well as adding fopen and fid to every fprintf call and finally fclose at the end of the function. Just as I wrote in my answer.

[Luisa Liboni]

I copied the the function to my working folder and changed its name to newsummary(); I call the function using this new name.

If I try to run it, even without hacking the code, this is, even without adding fopen and fid to every printf, I get this error:

Error using tabular/dotParenReference (line 69)
Unrecognized variable name 'getProperty'.

Error in newsummary (line 16)
descr = t.getProperty('Description',true);

[Stephen23]

@Luisa Liboni: you will have to do some digging around using the debugging tools. First check if that call works with the original summary file. Then set a breakpoint in the original summary file on that line. Run it. Check where that data is defined (use the editor). You might need to run the function several times and use the debugger to step through the functions... You will have to figure out what the difference is between the original function and your new copy, e.g. it might depend on some private functions. Dig around. Do not stop just because you get an error!

[Walter Roberson]

You could get that kind of problem when copying Mathworks code, if the function relies upon private functions instead of on functions that are on the regular path, or if the code relies upon a private property of a class (since you would not be executing in the context of the class.)

Answer 3

[Steven Lord]

Based on Luisa Liboni's most recent comment:

Okay, I understand your use case. How do you want to send this information to your people who are not MATLAB users? Copy and paste into an email, email it to them directly using the sendmail function, write it to a text file, publish it to a PDF / Word / HTML / LaTeX / etc. document, or some other approach?

Putting your call to summary inside a call to evalc would allow you to capture that text, though it does include the <strong> tag used to highlight the variable names.Here is some code that creates a table, summarizes it and captures the summary in a variable T, removes the tags used to highlight the variable names when the summary is shown in the Command Window, and copies that variable to the clipboard. Paste the contents of the clipboard into a document in the MATLAB Editor or your favorite text editor to see how that looks. You could write this to a text file using the normal file I/O functions in MATLAB, send it using sendmail, or do anything to it that you can do to a normal variable containing text.

% Make a sample table
load patients
patients = table(LastName,Gender,Age,Height,Weight,Smoker,Systolic,Diastolic);

% Capture the summary
T = evalc('summary(patients)');

% Remove the strong tags
T = erase(T, ["<strong>", "</strong>"]);

% Copy to the clipboard
clipboard('copy', T);

If you put the following three lines of code into a MATLAB script file in the MATLAB Editor, click the Publish tab of the Toolstrip, and press the Publish button you'll receive an HTML report. [Clicking the small triangle under the Publish button will let you publish to different formats, see this documentation page for more information.] For programmatic publishing, see the documentation for the publish function. Does the resulting HTML report look like something that your users could consume?

load patients
patients = table(LastName,Gender,Age,Height,Weight,Smoker,Systolic,Diastolic);
summary(patients)

[Walter Roberson]

matlab.internal.display.isHot would, I think, be false in -nodesktop mode, so if you were running without desktop, evalc() would not need to remove the <strong> tags.

... probably easier to just use the code to strip out the tags.