Error using mex: undefined reference for user build package

I run into the the following issue when I try to compile a user-build mex function :

>> mex kalcvf.c
Building with 'gcc'.

Error using mex
/tmp/mex_40203179616654_15298/kalcvf.o: In function `kalcvf':
kalcvf.c:(.text+0x120): undefined reference to `dcopy_'
(...)

the folder includes several files, such as

dlyap.c
kalcvf.c
kalcvf.def
kalcvf.vcproj
kalcvf.vcxproj
kalcvf.filters
kalcvf.user
matlib.c
matlib.h

and in a parent directory

mex.ncb
mex.sdf
mex.sln

What additional steps do I need to take in order to compile the mex function?

[Jan]

dcopy_ belongs the BLAS libraries. Did you include them?

mex kalcvf.c libmwlapack.lib libmwblas.lib

[Economist_101]

Jan, many thanks for this.

I indeed did not use those libraries (and did not know I should). Running the code returns the following error

Error using mex
gcc: error: libmwlapack.lib: No such file or directory
gcc: error: libmwblas.lib: No such file or directory

I did not find those files anywhere in my matlab folder, nor online. Where should I look? (I am running Matlab 2019a 64bit on a Linux Ubuntu 18.04).

Any pointer is much appreciated!

[Jan]

According to the documentation https://www.mathworks.com/help/matlab/matlab_external/calling-lapack-and-blas-functions-from-mex-files.html

mex -v -R2017b yourFcn.c -lmwblas

[MOVED to the section for answers]

[Economist_101]

Perfect, this did the trick:

mex -v -R2018a kalcvf/kalcvf.c kalcvf/dlyap.c kalcvf/matlib.c -lmwblas -lmwlapack

Answer 1

[Jan]

According to the documentation https://www.mathworks.com/help/matlab/matlab_external/calling-lapack-and-blas-functions-from-mex-files.html . E.g.:

mex -v -R2017b yourFcn.c -lmwblas

Answer 2

[James Tursa]

Try looking in the MATLAB/R2019a/extern/lib folder for versions of these files appropriate for your system. They might have slightly different names than above, but should have lapack and blas as part of the names.