Re: [Discuss-gnuradio] Problems with How to Write a Signal ProcessingBlock

[Eric Blossom]

On Tue, Jan 30, 2007 at 04:33:53PM -0700, Bahn William L Civ USAFA/DFCS wrote:
> As a test, I went into the howto_square_ff.cc file and changed it so
> that it adds instead of multiplies (so doubles instead of squares). The
> make check still passed without problems. If I introduced a syntax
> error, then it fails - so I am definitely changing the file being used
> in the make process.
> 
> This implies that the make check process is not actually invoking the
> qa_howto.py program. That being the case, upon what basis does the
> article claim that the new block works?


OK, I just tried this (including changing * to +).  
It worked as expected for me.

This is what I did.

Downloaded
ftp://ftp.gnu.org/gnu/gnuradio/gr-howto-write-a-block-3.0.2.tar.gz to ~/dl

  $ mkdir /tmp/test
  $ cd /tmp/test
  $ tar xzvf ~/dl/gr-howto-write-a-block-3.0.2.tar.gz
  $ cd gr-howto-write-a-block-3.0.2
  $ ./configure
  $ make
  $ make check

This worked fine.

Then I edited /tmp/test/gr-howto-write-a-block-3.0.2/src/lib/howto_square_ff.c
and changed the * to a + in line 88.

The, with my current directory set to /tmp/test/gr-howto-write-a-block-3.0.2

  $ make
  $ make check

And I get output like this (truncated)

Making check in python
make[2]: Entering directory `/tmp/test/gr-howto-write-a-block-3.0.2/src/python'
make  check-TESTS
make[3]: Entering directory `/tmp/test/gr-howto-write-a-block-3.0.2/src/python'
F.
======================================================================
FAIL: test_001_square_ff (__main__.qa_howto)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "./qa_howto.py", line 44, in test_001_square_ff
    self.assertFloatTuplesAlmostEqual (expected_result, result_data, 6)
  File "/usr/local/lib64/python2.4/site-packages/gnuradio/gr_unittest.py", line 
86, in assertFloatTuplesAlmostEqual
    self.assertAlmostEqual (a[i], b[i], places, msg)
AssertionError: 9 != -6.0 within 6 places

----------------------------------------------------------------------
Ran 2 tests in 0.014s

FAILED (failures=1)
FAIL: run_tests
===================
1 of 1 tests failed
===================
make[3]: *** [check-TESTS] Error 1
make[3]: Leaving directory `/tmp/test/gr-howto-write-a-block-3.0.2/src/python'
make[2]: *** [check-am] Error 2
make[2]: Leaving directory `/tmp/test/gr-howto-write-a-block-3.0.2/src/python'
make[1]: *** [check-recursive] Error 1
make[1]: Leaving directory `/tmp/test/gr-howto-write-a-block-3.0.2/src'
make: *** [check-recursive] Error 1


Looks good to me.

Eric