One workaround I’ve found is to quote the value, but adding a space. That is, ./blaa.py –xlim ” -2.e-3″ 1e4 This way argparse won’t think -2.e-3 is an option name because the first character is not a hyphen-dash, but it will still be converted properly to a float because float(string) ignores spaces on the left.
Let’s start by analysing the result of t – d. t is an unsigned int while d is an int, so to do arithmetic on them, the value of d is converted to an unsigned int (C++ rules say unsigned gets preference here). So we get 10u – 16u, which (assuming 32-bit int) wraps around … Read more
Python’s integers can grow arbitrarily large. In order to compute the raw two’s-complement the way you want it, you would need to specify the desired bit width. Your example shows -199703103 in 64-bit two’s complement, but it just as well could have been 32-bit or 128-bit, resulting in a different number of 0xf‘s at the … Read more
Can you use built-in functions? Because this is normally done using: max(0, points)
It looks like your implementation is probably doing an arithmetic bit shift with two’s complement numbers. In this system, it shifts all of the bits to the right and then fills in the upper bits with a copy of whatever the last bit was. So for your example, treating int as 32-bits here: nPosVal = … Read more
I don’t think hash values should be negative. Why not? It’s entirely valid to have negative hash codes. Most ways of coming up with a hash code naturally end up with negative values, and anything dealing with them should take account of this. However, I’d consider a different approach to coming up with your hash … Read more
Do floating point division then convert to an int. No extra modules needed. Python 3: >>> int(-1 / 2) 0 >>> int(-3 / 2) -1 >>> int(1 / 2) 0 >>> int(3 / 2) 1 Python 2: >>> int(float(-1) / 2) 0 >>> int(float(-3) / 2) -1 >>> int(float(1) / 2) 0 >>> int(float(3) / … Read more
The most recent example I can find is the UNISYS 2200 series, based on UNIVAC, with ones-complement arithmetic. The various models were produced between 1986 and 1997 but the OS was still in active development as late as 2015. They also had a C compiler, as seen here. It seems likely that they may still … Read more
sizeof returns an unsigned integer, so TOTAL_ELEMENTS is also unsigned. d is signed. Initially, d is -1. However, when doing the comparison, d is implicitly typecast to unsigned, so it is no longer -1 when being compared to TOTAL_ELEMENTS, it is actually UINT_MAX (which is 4294967295 on my machine, but might differ for others). Also, … Read more
The primary advantage of two’s complement over one’s complement is that two’s complement only has one value for zero. One’s complement has a “positive” zero and a “negative” zero. Next, to add numbers using one’s complement you have to first do binary addition, then add in an end-around carry value. Two’s complement has only one … Read more