Generate Single-Precision C Code Using the MATLAB Coder App
This example shows how to generate single-precision C code from double-precision MATLAB® code by using the MATLAB Coder™ app.
Prerequisites
To complete this example, install the following products:
MATLAB
MATLAB Coder
Fixed-Point Designer™
C compiler
See Supported Compilers.
You can use
mex -setup
to change the default compiler. See Change Default Compiler.
Create a Folder and Copy Relevant Files
Create a local working folder, for example,
c:\ex_2ndOrder_filter
.Change to the
docroot\toolbox\fixpoint\examples
folder. At the MATLAB command line, enter:cd(fullfile(docroot, 'toolbox', 'fixpoint', 'examples'))
Copy the
ex_2ndOrder_filter.m
andex_2ndOrder_filter_test.m
files to your local working folder.Type Name Description Function code ex_2ndOrder_filter.m
Entry-point MATLAB function Test file ex_2ndOrder_filter_test.m
MATLAB script that tests
ex_2ndOrder_filter.m
Open the MATLAB Coder App
Navigate to the work folder that contains the file for this example.
On the MATLAB Toolstrip Apps tab, under Code Generation, click the app icon.
Select the Source Files
To add the entry-point function ex_2ndOrder_filter
to
the project, browse to the file ex_2ndOrder_filter.m
,
and then click Open. By default, the app saves
information and settings for this project in the current folder in
a file named ex_2ndOrder_filter.prj
.
Enable Single-Precision Conversion
Set Numeric Conversion to
Convert to single precision
.Click Next to go to the Define Input Types step.
The app screens
ex_2ndOrder_filter.m
for code violations and code generation readiness issues. The app does not find issues inex_2ndOrder_filter.m
.
Define Input Types
On the Define Input Types page, to add
ex_2ndOrder_filter_test
as a test file, browse toex_2ndOrder_filter_test
. Click Open.Click Autodefine Input Types.
The test file runs and displays the outputs of the filter for each of the input signals. The app determines that the input type of
x
isdouble(1x256)
.Click Next to go to the Check for Run-Time Issues step.
Check for Run-Time Issues
To detect and fix single-precision conversion issues, perform the Check for Run-Time Issues step.
On the Check for Run-Time Issues page, the app populates the test file field with
ex_2ndOrder_filter_test
, the test file that you used to define the input types.Click Check for Issues.
The app generates a single-precision MEX function from
ex_2ndOrder_filter
. It runs the test fileex_2ndOrder_filter_test
replacing calls toex_2ndOrder_filter
with calls to the generated MEX function. If the app finds issues, it provides warning and error messages. Click a message to highlight the problematic code in a window where you can edit the code. In this example, the app does not detect issues.Click Next to go to the Generate Code page.
Generate Single-Precision C Code
In the Generate dialog box, set Build type to
Static Library
.Set Language to C.
For other settings, use the default values.
To generate the code, click Generate.
MATLAB Coder builds the project and generates a C static library and supporting files in the default subfolder,
codegen/lib/ex_2ndOrder_filter
.
View the Generated C Code
The app displays the generated code for ex_2ndOrder_filter.c
.
Double-precision variables have type
float
in the C code.The index
i
is an integer.
View Potential Data Type Issues
When you generate single-precision code, the app enables highlighting of potential data type issues in the code generation report. If the app cannot remove a double-precision operation, the report highlights the MATLAB expression that results in the operation.
To open the code generation report, click the View Report link.
Click the Code Insights tab. Expand Potential data type issues. The absence of double-precision operations indicates that no double-precision operations remain.