Console showing "memory error"

[bob2]

Attempted to run the code and this message popped up:

MemoryError: memory allocation failed, allocating %u bytes

What does this mean?

[jpearman]

It means you ran out of memory, probably the Python code is too big.

[bob2]

How many lines can the brain handle?

[jpearman]

@bob2

How many lines can the brain handle?

It’s not as simple as that
IIRC, source code size needs to be below 32k, but then the Python VM needs to be able to turn that into byte code, so program complexity also is a factor.

This is one of the big downsides to using Python (which blocks converts to) rather than C on the IQ generation 2 brain.

send feedback with the program open and I can take a look if you want me to.

discussion about this a couple of years ago.

VEX IQ Robot Brain Gen 2 -- Memory Allocation Error

For Python, there’s no fixed formula. There a maximum size the source can be (your code was at about 75% of that limit) but then the VM has to convert the source to bytecode and that’s far more dependent on the number of variables, functions etc. and is not easy to calculate. C code is easier to handle in this respect. The limit is determined by available RAM, so no, not really possible. Your code would compile on an EXP brain which has approximately 5 x available memory for user programs …

[bob2]

Do I just screenshot the code?

[jpearman]

@bob2

Do I just screenshot the code?

No, use the feedback button in VEXcode (top right) to send feedback to VEX.

[jpearman]

yea, program is too big and too complex for the Python VM

[Foster]

@bob2 I would love to know what you are doing to exceed the memory amounts.

@jpearman Is the heap management available to V2 users?

[jpearman]

@Foster

I would love to know what you are doing to exceed the memory amounts.

It was a really big block program generating > 32k of Python code. It also ran out of memory when trying to compile.

@Foster

Is the heap management available to V2 users?

The problem is that IQ2 has (relatively) little memory, I can only set the heap size at 56k, yes the garbage collection is available to use, but the problem with really big programs is that there’s not enough heap to even compile them to byte code. This was all good for V5 (1MB heap) and EXP within reason (368k), but it’s not ideal on IQ2, I have no good solution that doesn’t involve converting to byte code externally and running that (which I could do at one point but the capability may have been removed).

I could run bob2’s code easily when converted to C++, but it’s a one way process and would be a bit awkward to keep editing in blocks and converting to a C++ project for download (with the risk of accidentally loosing the blocks project)

[jpearman]

The web version of VEXcode would not create the PDF share of the project, the desktop version would but not very user friendly, here just a section of one page, more like this on other pages.

I don’t know if restructuring the code with less long if-then-else chains would help.

[Foster]

I’d guess that a restructure would help. Anytime you get that much in if then else blocks, it screams for functions. And there are ways to push the way functions store data. But that may be well above their skill level.

Two weeks ago I would have offered to see if I could do a quick refactor. But Friday is the first of 11 back to back Friday or Saturday events, so I’m swamped.

Thanks James for the response.

[bob2]

Redone, it works under the memory limit now