generate.py failure case

[alanvgreen]

This input file causes generate.py to crash:

{
  "version": 1,
  "description": "Generates patterns.",
  "inputs": ["t", "u"],
  "outputs": {
    "A": [1, 0, 0, 0],
    "G": [0, 0, 0, 1]
  }
}

Here is the output from the failing run:

$ python3 generate.py -v -f logic.json -o logic.wokwi
[    INFO] Log level: INFO
[    INFO] Data is read from input file 'logic.json'
[    INFO] Inputs:     2 ['t', 'u']
[    INFO] Outputs:    2 ['A', 'G']
[    INFO]   Output A: [1, 0, 0, 0]; ones: [0]
[    INFO]   Output G: [0, 0, 0, 1]; ones: [3]
Traceback (most recent call last):
  File "/home/osboxes/src/wokwi-lookup-table-generator/generate.py", line 441, in <module>
    logic_meta[output]["qm_terms_raw"] = list( q.simplify(logic[output]) ) # convert set into list (to allow indexing)
  File "/home/osboxes/venvs/py/lib/python3.9/site-packages/quine_mccluskey/qm.py", line 130, in simplify
    return self.simplify_los(ones, dc)
  File "/home/osboxes/venvs/py/lib/python3.9/site-packages/quine_mccluskey/qm.py", line 193, in simplify_los
    essential_implicants = self.__get_essential_implicants(prime_implicants, set(dc))
  File "/home/osboxes/venvs/py/lib/python3.9/site-packages/quine_mccluskey/qm.py", line 419, in __get_essential_implicants
    perms[t] = set(p for p in self.permutations(t) if p not in dc)
  File "/home/osboxes/venvs/py/lib/python3.9/site-packages/quine_mccluskey/qm.py", line 419, in <genexpr>
    perms[t] = set(p for p in self.permutations(t) if p not in dc)
  File "/home/osboxes/venvs/py/lib/python3.9/site-packages/quine_mccluskey/qm.py", line 532, in permutations
    if value[i] == '0' or value[i] == '1':
IndexError: string index out of range

If I change the line for "A" to:

    "A": [0, 0, 1, 0],

then generate.py succeeds:

$ python3 generate.py -v -f logic.json -o logic.wokwi
[    INFO] Log level: INFO
[    INFO] Data is read from input file 'logic.json'
[    INFO] Inputs:     2 ['t', 'u']
[    INFO] Outputs:    2 ['A', 'G']
[    INFO]   Output A: [0, 0, 1, 0]; ones: [2]
[    INFO]   Output G: [0, 0, 0, 1]; ones: [3]
[    INFO] Calculated CNF for output A: t~u
[    INFO] Calculated CNF for output G: tu
[    INFO] Estimated parts usage:
[    INFO]     *   4 buffers (for the inputs and the outputs)
[    INFO]     *   2 NOT gate(s) (for the negated inputs)
[    INFO]     *   2 two-input AND gate(s), in max. 1 stages
[    INFO]     * number of two-input OR gate(s) not estimated yet
[    INFO] 
[    INFO] Connecting inputs with first stage of AND gates for every output.
[    INFO] Connecting input inside the wokwi design to first AND gate stage (later used for output A)...
[    INFO] All AND gates required in the first AND gate stage for output A: [[0]]
[    INFO] Connecting input inside the wokwi design to first AND gate stage (later used for output G)...
[    INFO] All AND gates required in the first AND gate stage for output G: [[1]]
[    INFO] Connecting inputs with first stage of AND gates for every output completed.
[    INFO] 
[    INFO] Merges all first stage AND gates down to a single 'root' AND gate (for every term of every output)
[    INFO] Single AND gate #0 does not need to be merged.
[    INFO] Remaining AND gates (final stage): [0] for the output A to be connected to OR gates
[    INFO] Single AND gate #1 does not need to be merged.
[    INFO] Remaining AND gates (final stage): [1] for the output G to be connected to OR gates
[    INFO] Merges of all first stage AND gates down to a single 'root' AND gate completed.
[    INFO] 
[    INFO] Combining mini terms: Create first stage of OR gates (in order to OR all terms for every output) 
[    INFO] and connect the AND gate from the previous stage (=the final AND stage) to it.
[ WARNING] Single mini term for output A: AND gate output (AND gate #0)
[ WARNING] Creating a dummy OR gate (which does not need to be then merged down).
[    INFO] First stage of OR gates (connected to AND gates): [0] for output A
[ WARNING] Single mini term for output G: AND gate output (AND gate #1)
[ WARNING] Creating a dummy OR gate (which does not need to be then merged down).
[    INFO] First stage of OR gates (connected to AND gates): [1] for output G
[    INFO] Done combining mini terms (AND gates) by first stage of OR gates.
[    INFO] 
[    INFO] Merges all first stage OR gates down to a single 'root' OR gate and connect them to the output buffers
[    INFO] Performing the merges of all OR gates for output A
[    INFO] Number of OR gates to be merged: 1, i.e. [0]
[    INFO] Only single OR gate, therefore directly connect it to the output buffer
[    INFO] Identified #0 as final OR gate for the output A to be connected to output buffer
[    INFO] Performing the merges of all OR gates for output G
[    INFO] Number of OR gates to be merged: 1, i.e. [1]
[    INFO] Only single OR gate, therefore directly connect it to the output buffer
[    INFO] Identified #1 as final OR gate for the output G to be connected to output buffer
[    INFO] Max AND gate stages: 1
[    INFO] Max  OR gate stages: 1
[    INFO] Finished the wokwi design!
[    INFO] Writing final wokwi design file 'logic.wokwi'...

(PS: Love the idea of this tool. Thank you for writing it!!)

[maehw]

Hi @alanvgreen !

Thank you for your report. I can reproduce the error (and the fix) locally.

The root cause seems to be inside of quine_mccluskey/qm.py - or how I am using it as dependency.
It's an interesting find and may be an off-by-1 error. I can have a look at it, but unfortunately very unlikely today.