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Results logged by instrumented, compiled C code function


showInstrumentationResults('mex_fcn') opens the Instrumentation Report Viewer, showing results from calling the instrumented MEX function mex_fcn.

Hovering over variables and expressions in the report displays the logged information. The logged information includes minimum and maximum values, proposed fraction or word lengths, percent of current range, and whether the value is always a whole number, depending on which options you specify. If you specify to include them in the buildInstrumentedMex function, histograms are also included. The same information is displayed in a summary table in the Variables tab.

When you call showInstrumentationResults, a file named instrumentation/mex_fcn/html/printable.html is created. mex_fcn is the name of the corresponding instrumented MEX function. Selecting this file opens a web-based version of the Instrumentation Report Viewer. To open this file from within MATLAB®, right-click on the file and select Open Outside MATLAB.

showInstrumentationResults returns an error if the instrumented mex_fcn has not yet been called.

showInstrumentationResults('mex_fcn','-options') specifies options for the instrumentation results section of the Instrumentation Report Viewer.


showInstrumentationResults mex_fcn and showInstrumentationResults mex_fcn -options are alternative syntaxes for opening the Instrumentation Report Viewer.


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Generate an instrumented MEX function, then run a test bench. Use showInstrumentationResults to open the Instrumentation Report Viewer.


The logged results from showInstrumentationResults are an accumulation of all previous calls to the instrumented MEX function. To clear the log, see clearInstrumentationResults.

Create a temporary directory, then import an example function.


Define prototype input arguments.

T = numerictype('DataType','ScaledDouble','Scaling',...

n = 128;
x = complex(fi(zeros(n,1),T));
W = coder.Constant(fi(fidemo.fi_radix2twiddles(n),T));

Generate an instrumented MEX function. Use the -o option to specify the MEX function name.

buildInstrumentedMex testfft -o testfft_instrumented...
   -args {x,W} -histogram

Run a test bench to record instrumentation results. showInstrumentationResults to open a report. View the simulation minimum and maximum values, proposed fraction length, percent of current range, and whole number status by pausing over a variable in the report.

for i=1:20
   x(:) = 2*rand(size(x))-1;
   y = testfft_instrumented(x);

Use showInstrumentationResults to open a report of the instrumentation results. To view the simulation minimum and maximum values, proposed fraction length, percent of current range, and whole number status, pause over a variable in the report.

showInstrumentationResults testfft_instrumented...
   -proposeFL -percentSafetyMargin 10

Screenshot of Instrumentation Report Viewer.

View the histogram for a variable by selecting the histogram icon in the Variables tab to open the Numeric Type Scope.

Screenshot of Numeric Type Scope.

Close the histogram display and then, clear the results log.

clearInstrumentationResults testfft_instrumented

Clear the MEX function, then delete temporary files.

clear testfft_instrumented;

Input Arguments

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Instrumented MEX function created using buildInstrumentedMex.

Instrumentation results options, specified as:

-defaultDT T

Default data type to propose for double or single data type inputs, where T is either a numerictype object or one of the following: 'remainFloat' (default), 'double', 'single', 'int8', 'int16', 'int32', 'int64', 'uint8', 'uint16', 'uint32', or 'uint64'.

If you specify an int or uint, the signedness and word length are that int or uint value and a fraction length is proposed.

The default is remainFloat, which does not propose any data types.


Do not display MATLAB code in the printable report. Display only the tables of logged variables. This option only has effect in combination with the -printable option.


Optimize the word length of variables whose simulation min/max logs indicate that they are always whole numbers.

-percentSafetyMargin N

Safety margin for simulation min/max, where N is a percent value.


Create and open a printable HTML report. The report opens in the system browser.


Propose fraction lengths for specified word lengths.


Propose word lengths for specified fraction lengths.

Version History

Introduced in R2011b

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