# Assertion error beyond 4096 output items

**URL:** <https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047>\
**Category:** GNU Radio\
**Created:** [May 28, 2014, 9:46am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047 "2014-05-28T09:46:40Z")\
**Posts on this page:** 19\
**Page:** 1

<div class="post-metadata">

**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\
**Post date:** [May 28, 2014, 9:46am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/1 "2014-05-28T09:46:40Z")

</div>

Hi  
we have written a c++ block using out of tree modules which uses a  
sync  
block that outputs same no of items as input items given. we have  
written a  
python test file where the inputs and outputs are complex floats. The  
test  
code is running well until 4096 items. But when the output items size  
is  
greater than or equal to 8192, ctest shows an assertion error which  
says

-10+5j !=10+5j beyond 7 places.

we are unsure what the error is. Is it got something to do with gnuradio  
architecture with limitation beyond 4096\*2 items or is it anything else  
we  
are doing wrong. I cannot see an error in the logic of the program. I  
can  
attach the program if necessary.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 10:17am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/2 "2014-05-28T10:17:46Z")

</div>

Hi Karan,

how does your test look like?  
Usually, to test a blocks functionality, you construct a minimal flow  
graph in the python test script:  
vector\_source-\>block under test-\>vector sink  
fill it with sample data, and let GNU Radio run that flowgraph.  
Then you have no control on how large your noutput\_items is, because  
this is up to GNU Radio to decide  
at runtime.  
Generally, it’d be nice to know which version of GNU Radio you are  
running etc.  
If you want to share your code, best way to do this is usually either  
pasting just the C++ block and the python test to  
pastebin or [gist.github.com](http://gist.github.com), or even better, making a git repo out of  
your project and pushing it to github or similar.

Greetings,  
Marcus

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 11:15am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/3 "2014-05-28T11:15:39Z")

</div>

On 28.05.2014 09:45, Karan T. wrote:

> Hi  
> we have written a c++ block using out of tree modules which uses a  
> sync block that outputs same no of items as input items given. we have  
> written a python test file where the inputs and outputs are complex  
> floats. The test code is running well until 4096 items. But when the  
> output items size is greater than or equal to 8192, ctest shows an  
> assertion error which says
> 
> -10+5j !=10+5j beyond 7 places.

This looks like floating point quantization errors. Show us your QA, and  
make sure you’re using the assertFloatTuplesAlmostEqual (not sure if  
that’s the right name) call.

M

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 11:30am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/4 "2014-05-28T11:30:02Z")

</div>

On 28.05.2014 11:13, Martin B. wrote:

> This looks like floating point quantization errors. Show us your QA, and  
> make sure you’re using the assertFloatTuplesAlmostEqual (not sure if  
> that’s the right name) call.

Ah, as Marcus M points out, this is a signature error, rather than  
quantization 🙂  
Still, this all points to your code being incorrect, or your QA making  
invalid assumptions.

Maybe you should be tracking state in your block (these number indicate  
that more than 1 work function call seem unveil your bug).

M

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 12:01pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/5 "2014-05-28T12:01:44Z")

</div>

@Marcus. Instead of using a grc gui flowgraph to test our block, we  
have  
written a qa test code in python which connects vector source, block  
that  
we are testing and vector sink just like the example given in out of  
tree  
modules to generate square of the input items.

We are writing an alamouti code block which takes in an input stream of  
N  
complex numbers and gives out 2 output steams of N items each. I will  
attach the C++ code of block( [/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This - Pastebin.com](http://pastebin.com/Kdnk1t8x) ) and also  
the  
python qa test code below([#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)).  
[http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 12:12pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/6 "2014-05-28T12:12:18Z")

</div>

Your Problem is actually here:  
(C++ work function)  
" while ( i \< d\_fft\_length ) {"

you never check that your in[] and out[] indices are within  
noutput\_items!  
You only get a limited amount of items per work call. For sync blocks,  
this is noutput\_items.  
What you do is just ignore that number, take d\_fft\_length items (whether  
there are more or less  
available) and process them. Then you “return noutput\_items”, which is  
also wrong,  
because you actually process d\_fft\_length.

What you most probably want to do is either directly process vectors, or  
set an output multiple.  
A vector is actually just an item with vector\_length\*single\_itemsize  
size, so you need to change your in- and  
output signatures by multiplying sizeof(whatever) with fft\_length; then,  
in your work, you only process  
one vector, thus you should return 1;.

If you use set\_output\_multiple, your item size stays the same  
(sizeof(gr\_complex)), and you don’t have to change your code,  
aside from replacing return noutput\_items by what you’ve actually  
consumed (ie. d\_fft\_length).

Greetings,  
Marcus

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 2:45pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/7 "2014-05-28T14:45:24Z")

</div>

Hi Marcus,  
Thank you for evaluating our code and help debugging  
it.  
what we understand from your reply is that work function at a time  
processes noutput\_items and this can be lesser than or more than the  
fft\_length. As an example in our code when we give the fft length as  
8192,  
but the noutput\_items is still 4096, so does that mean it has to  
execute  
work function twice to process 4096\*2=8192 items?

Regarding the first approach you suggested, we change the input  
signature  
and output signature to (sizeof (gr\_complex)\*fft\_length) so that it is a  
single vector that is being processed. Then we return 1 as suggested.  
But  
it is throwing an itemsize mismatch error. I have attached the c++ file  
here ( [/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This - Pastebin.com](http://pastebin.com/TKemtbxN) ). The error says

## ERROR: test\_001\_t ( **main**.qa\_al\_enc) 2: ------------------------------

2: Traceback (most recent call last):  
2: File “/home/sagar/gr-alamouti/python/qa\_al\_enc.py”, line 66, in  
test\_001\_t  
2: self.tb.connect(src,opr)  
2: File  
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top\_block.py”, line  
130, in connect  
2: self.\_connect(points[i-1], points[i])  
2: File  
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top\_block.py”, line  
142, in \_connect  
2: dst\_block.to\_basic\_block(), dst\_port)  
2: File  
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/runtime\_swig.py”,  
line  
4350, in primitive\_connect  
2: return \_runtime\_swig.top\_block\_sptr\_primitive\_connect(self,  
\*args)  
2: ValueError: itemsize mismatch: vector\_source\_c1:0 using 8, al\_enc1:0  
using 65536

The python qa file link is ([#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)).  
[http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)

For the second method suggested should we write a general work function  
and  
a forecast function which would mean doing away with sync block that we  
are  
using with work function right now?  
[http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 12:03pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/8 "2014-05-28T12:03:36Z")

</div>

Hi!

On 28.05.2014 12:00, Karan T. wrote:

> @Marcus. Instead of using a grc gui flowgraph to test our block, we have  
> written a qa test code in python which connects vector source, block that  
> we are testing and vector sink just like the example given in out of tree  
> modules to generate square of the input items.  
> Excellent, that’s what I meant to suggest 🙂  
> We are writing an alamouti code block which takes in an input stream of N  
> complex numbers and gives out 2 output steams of N items each. I will  
> attach the C++ code of block( [/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This - Pastebin.com](http://pastebin.com/Kdnk1t8x) ) and also the  
> python qa test code below([#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)).  
> [http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)  
> Thanks, will have a look at it.

Greetings,  
Marcus

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 8:43am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/9 "2014-05-29T08:43:12Z")

</div>

Hi All,  
@Marcus @activecat @Martin Thank you all for your help. We  
were  
able to solve the problem we had for itemsize greater than or equal to  
8192. We used set\_output\_multiple(fft\_length) in the constructor and it  
worked. Now it is working for any input fft length.

So at the input of the C++ we are giving vector\_source\_c() and then  
input  
output signatures are sizeof(gr\_complex). The work function is taking  
noutput\_items and returning noutput\_items. We understand now that  
because  
we have used set\_output\_multiple(fft\_length) in the constructor, the  
noutput\_items is fixed at the fft\_length and then work function is being  
called.

However one small doubt,when we print value of noutput\_items in C++  
program  
inside the work function ,the print statement is executed twice for any  
fft\_length we use. Is this correct? It should only print once the value  
of  
noutput\_items if i am right.

Thank you once again.

On Thu, May 29, 2014 at 2:53 AM, Marcus Müller  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 5:16pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/10 "2014-05-28T17:16:32Z")

</div>

Hi Karan,  
You keep Marcus very busy, let me help to offload him.

On Wed, May 28, 2014 at 8:36 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Hi Marcus,  
> Thank you for evaluating our code and help debugging it. what we  
> understand from your reply is that work function at a time processes  
> noutput\_items and this can be lesser than or more than the fft\_length. As  
> an example in our code when we give the fft length as 8192, but the  
> noutput\_items is still 4096, so does that mean it has to execute work  
> function twice to process 4096\*2=8192 items?

When the desirable fft\_length is 8192, could you accept to perform FFT  
at  
only 4096 elements?  
If yes, perform FFT on this 4096 elements, and return 4096.  
If not, make sure you use set\_output\_multiple(fft\_length) or at least  
set\_min\_noutput\_items(fft\_length), in this case the scheduler will not  
call  
work() function with insufficient number of elements.

> Regarding the first approach you suggested, we change the input signature  
> and output signature to (sizeof (gr\_complex)\*fft\_length) so that it is a  
> single vector that is being processed. Then we return 1 as suggested. But  
> it is throwing an itemsize mismatch error. I have attached the c++ file  
> here ( [/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This - Pastebin.com](http://pastebin.com/TKemtbxN) ). The error says

The correct way is, in your work() function you should have 2 loops,  
because now your in[0] is a vector but no longer solely a complex  
number.  
Example:

for (int i=0; i \< noutput\_items; i++)  
{  
for (int j=0; j \< fft\_length; j++)  
{  
…  
}  
}

For the second method suggested should we write a general work function  
and

> a forecast function which would mean doing away with sync block that we are  
> using with work function right now?

No need, because set\_output\_multiple() works with sync block as well.

Note:  
Apologize in advance if my answer is incorrect.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 9:03am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/11 "2014-05-29T09:03:42Z")

</div>

On Thu, May 29, 2014 at 2:41 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> So at the input of the C++ we are giving vector\_source\_c() and then input  
> output signatures are sizeof(gr\_complex). The work function is taking  
> noutput\_items and returning noutput\_items. We understand now that because  
> we have used set\_output\_multiple(fft\_length) in the constructor, the  
> noutput\_items is fixed at the fft\_length and then work function is being  
> called.

The noutput\_items could be fft\_length or multiple of fft\_length.  
Says fft\_length is 8192, then noutput\_items could be either 8192, 16384  
or  
24576 etc, determined by the scheduler.  
If you only get noutput\_items equals to 8192, that could be due to the  
number of input elements available is less than 16384.

> However one small doubt,when we print value of noutput\_items in C++  
> program inside the work function ,the print statement is executed twice for  
> any fft\_length we use. Is this correct? It should only print once the  
> value of noutput\_items if i am right.

If the print statement is executed twice, that means the work() function  
is  
invoked twice.  
It could be something wrong with your code, let’s show your code here.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 28, 2014, 11:24pm UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/12 "2014-05-28T23:24:56Z")

</div>

Hi Activecat, hi Karan!

> You keep Marcus very busy, let me help to offload him.

Activecat: Thanks 🙂 I’m not in charge of the mailing list, everyone  
should feel free to  
answer if he’s able to help! Helping Karan was, by the way, not the  
biggest of all  
work loads, because I always enjoy reading a few lines of code. But as  
you will see, there’s not  
much to add to your explanations, so keep that good work up 😉

So, back to topic:

> > Hi Marcus,  
> > Thank you for evaluating our code and help debugging it. what we  
> > understand from your reply is that work function at a time processes  
> > noutput\_items  
> > Sorry, you got that wrong:  
> > The work function processes as many items as _you_ define by returning  
> > that number.  
> > The upper boundary is the number of items available, which is  
> > noutput\_items.  
> > All items that have been available but you haven’t consumed (by  
> > returning less than noutput\_items) will be saved for the next work call.

> > and this can be lesser than or more than the fft\_length. As  
> > an example in our code when we give the fft length as 8192, but the  
> > noutput\_items is still 4096, so does that mean it has to execute work  
> > function twice to process 4096\*2=8192 items?  
> > Usually, there’s no guarantee that your work will always be called with  
> > the same number of items.  
> > The only guarantee you get is that noutput\_items \>= 1 !  
> > So if you want to make sure you always get a certain number of items or  
> > vectors of the right length, you will  
> > have to use set\_output\_multiple or a vector input length.

> […]
> 
> If not, make sure you use set\_output\_multiple(fft\_length) or at least  
> set\_min\_noutput\_items(fft\_length), in this case the scheduler will not call  
> work() function with insufficient number of elements.  
> Exactly!
> 
> > Regarding the first approach you suggested, we change the input signature  
> > and output signature to (sizeof (gr\_complex)\*fft\_length) so that it is a  
> > single vector that is being processed. Then we return 1 as suggested. But  
> > it is throwing an itemsize mismatch error. I have attached the c++ file  
> > here ( [/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This - Pastebin.com](http://pastebin.com/TKemtbxN) ). The error says  
> > This is because you put in items of sizeof(gr\_complex), but your block  
> > expects sizeof(gr\_complex)_fft\_length. Solve this setting the vector  
> > length of your vector source OR by adding a “stream to vector” block; do  
> > the same for your sink OR add a “vector to stream”.  
> > The correct way is, in your work() function you should have 2 loops,  
> > because now your in[0] is a vector but no longer solely a complex number.  
> > As GNU Radio is now, this is not really true. Since vectors are but  
> > vector elements that are directly sequential in memory, and these  
> > vectors, like smaller items, are directly sequential in memory  
> > themselves, there is no difference between 16384 items in two items of  
> > length 8192_sizeof(gr\_complex) and 16384 items of sizeof(gr\_complex).  
> > It’s always good to remember: As a rule of thumb, the GNU Radio  
> > scheduler does not care about your signal at all 😃 it only cares about  
> > memory sizes. That’s why it complains about item size mismatches – it  
> > has no way to look inside the data!

> For the second method suggested should we write a general work function and
> 
> > a forecast function which would mean doing away with sync block that we are  
> > using with work function right now?
> 
> No need, because set\_output\_multiple() works with sync block as well.  
> Exactly. Whenever you can say that for a certain amount of input, there  
> will be a proportional amount of output items, there’s no need for  
> general\_work, and you can use the sync, interpolator or decimator block  
> types.

Greetings,  
Marcus

Note:

> Note:  
> Apologize in advance if my answer is incorrect.

Activecat, you’re already a rising star 😉 so as a GNU Radio enthusiast  
I really like when you bring yourself in! I’ve made dozens of mistakes,  
and I never felt bad when someone corrected me afterwards, and you  
shouldn’t either.  
If GNU Radio was for people that are perfect, then this project would be  
as dead as a doornail, and as beginner-friendly as parachute-free  
skydiving…  
Software frameworks (heck, we call ourselves “ecosystem”) like GNU Radio  
only blossom when people discuss concepts, and that won’t happen when  
everyone has the same understanding and the same problems. So I  
encourage everyone to experiment a lot, and ask questions that they  
can’t solve themselves! Answering questions definitively belongs into  
the community part of experimenting and should be fruitful to both, the  
one asking and the one answering.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 9:13am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/13 "2014-05-29T09:13:40Z")

</div>

@Activecat Here is the c++ block code

> **[/\* -\*- c++ -\*- \*//\* \* Copyright 2014 \<+YOU OR YOUR COMPANY+\>. \* \* This...](https://pastebin.com/0y1b9guh)**
>
> Pastebin.com is the number one paste tool since 2002. Pastebin is a website where you can store text online for a set period of time.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 10:25am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/14 "2014-05-29T10:25:42Z")

</div>

On Thu, May 29, 2014 at 3:12 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> @Activecat Here is the c++ block code

Let’s change the print statement to below, recompile, run and paste the  
console output here.

std::cout \<\< “al\_enc::work: noutput\_items=” \<\< noutput\_items \<\<  
std::endl;

Also, what did you configure on the vector\_source\_c ?

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 11:21am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/15 "2014-05-29T11:21:22Z")

</div>

On Thu, May 29, 2014 at 4:54 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Done constructing a list of tests

This is unittest, not the application flowgraph.

Unittest is used to verify your code.  
Application flowgraph is used to run RF simulations.

In application flowgraph, if you only have 8192 inputs while the  
fft\_length  
is set to 8192, then the work() should be called only once.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 10:55am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/16 "2014-05-29T10:55:35Z")

</div>

We changed the print statement to what you said and console output is

sagar@Horus:~/gr-alamouti/  
build$ ctest -V -R al\_enc  
UpdateCTestConfiguration from  
:/home/sagar/gr-alamouti/build/DartConfiguration.tcl  
UpdateCTestConfiguration from  
:/home/sagar/gr-alamouti/build/DartConfiguration.tcl  
Test project /home/sagar/gr-alamouti/build  
Constructing a list of tests  
Done constructing a list of tests  
Checking test dependency graph…  
Checking test dependency graph end  
test 2  
Start 2: qa\_al\_enc

## 2: Test command: /bin/sh “/home/sagar/gr-alamouti/build/python/qa\_al\_enc\_test.sh” 2: Test timeout computed to be: 9.99988e+06 2: al\_enc::work:noutput\_items1024 2: al\_enc::work:noutput\_items1024 2: . 2:

2: Ran 1 test in 0.014s  
2:  
2: OK  
1/1 Test #2: qa\_al\_enc … Passed 0.21 sec

The following tests passed:  
qa\_al\_enc

100% tests passed, 0 tests failed out of 1

Total Test time (real) = 0.21 sec

Vector\_source\_c takes in an argument numb which is a list that contains  
fft\_size values. I will paste the qa code  
here([#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)).  
[http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 11:51am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/17 "2014-05-29T11:51:50Z")

</div>

On Thu, May 29, 2014 at 4:54 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Done constructing a list of tests

Are you sure this is from the code unmodified at  
[#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B) ?  
You configured n=2048 but the work() is called with noutput\_items=1024.  
Earlier you said it worked well.

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 30, 2014, 6:56am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/18 "2014-05-30T06:56:33Z")

</div>

On Thu, May 29, 2014 at 4:54 PM, Karan T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Vector\_source\_c takes in an argument numb which is a list that contains  
> fft\_size values. I will paste the qa code here([#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)).  
> [http://pastebin.com/da21Ww4B](http://pastebin.com/da21Ww4B)

Something a little bit out of topic:  
Part of your code at [#!/usr/bin/env python# -\*- coding: utf-8 -\*-# # Copyright 2014 \<+YOU OR YO - Pastebin.com](http://pastebin.com/da21Ww4B)

```
    numb=list()
    for i in range (n):
            numb.append(complex(lst1[i],lst2[i]))

```

Above code is not “vectorized”.  
The vectorized version may look like:

```
    numb = numpy.complex64( lst1 ) + 1j * numpy.complex64( lst2 )

```

Vectorization is probably less critical in unittest, but should not be  
overlooked for blocked coded in python.  
For info about vectorization,  
[http://www.mathworks.com/help/matlab/matlab\_prog/vectorization.html](http://www.mathworks.com/help/matlab/matlab_prog/vectorization.html)

---

<div class="post-metadata">

**Author:** ![karan\_t](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/e47774/32.png) [@karan\_t](https://www.ruby-forum.com/u/karan_t)\
**Post date:** [May 29, 2014, 11:56am UTC](https://www.ruby-forum.com/t/assertion-error-beyond-4096-output-items/230047/19 "2014-05-29T11:56:31Z")

</div>

Activecat,  
I am sorry, I pasted the wrong qa code. I changed  
value  
of n to n=1024 and then when i printed it, I got the output I pasted  
above.