divide-by-zero

How to cause an intentional division by zero?

由 无人久伴 提交于 2019-12-08 15:31:51
问题 For testing reasons I would like to cause a division by zero in my C++ code. I wrote this code: int x = 9; cout << "int x=" << x; int y = 10/(x-9); y += 10; I see "int =9" printed on the screen, but the application doesn't crash. Is it because of some compiler optimizations (I compile with gcc)? What could be the reason? 回答1: Make the variables volatile . Reads and writes to volatile variables are considered observable: volatile x = 1; volatile y = 0; volatile z = x / y; 回答2: Because y is not

How to eliminate “divide by 0” error in template code

由 坚强是说给别人听的谎言 提交于 2019-12-08 15:15:13
问题 I'm using a pair of integer template parameters to specify a ratio, since I can't use a double as a template parameter. The conversion into a double is protected against divide-by-zero with a ternary. This worked in an earlier version of the compiler, but Visual Studio 2013 gives an error: error C2124: divide or mod by zero Here's a simplified version of the code: template<int B1, int B2> class MyClass { const double B = (B2 == 0) ? 0.0 : (double) B1 / (double) B2; // ... }; MyClass<0, 0>

Where is the “Zero divide” done in kernel for Arm Cortex A-9

由 半城伤御伤魂 提交于 2019-12-08 08:56:16
问题 I am looking into kernel source code (2.6.35 ) for Zero divide . I inserted Zero divide in user space program and all threads stopped. So I want to know Where is the "Zero divide" done in kernel for Arm Cortex A-9? I am not able to find any trap for this .... Thanks 回答1: It depends on the architecture. Given the following user space code on an x86 system : main() { int x = 42 / 0; } the compiler inserts a idivl command into the object code. When this command is executed with a divisor of 0,

Linear Programming - variable that equals the sign of an expression

由 萝らか妹 提交于 2019-12-07 12:58:25
问题 I am trying to write a linear program and need a variable z that equals the sign of x-c, where x is another variable, and c is a constant. I considered z = (x-c)/|x-c| . Unfortunately, if x=c, then this creates division by 0. I cannot use z=x-c, because I don't want to weight it by the magnitude of the difference between x and c. Does anyone know of a good way to express z so that it is the sign of x-c? Thank you for any help and suggestions! 回答1: You can't model z = sign(x-c) exactly with a

How to get Python division by -0.0 and 0.0 to result in -Inf and Inf, respectively?

由 大兔子大兔子 提交于 2019-12-06 20:46:12
问题 I have a situation where it is reasonable to have a division by 0.0 or by -0.0 where I would expect to see +Inf and -Inf, respectively, as results. It seems that Python enjoys throwing a ZeroDivisionError: float division by zero in either case. Obviously, I figured that I could simply wrap this with a test for 0.0. However, I can't find a way to distinguish between +0.0 and -0.0. (FYI you can easily get a -0.0 by typing it or via common calculations such as -1.0 * 0.0). IEEE handles this all

Safe Floating Point Division

由 扶醉桌前 提交于 2019-12-06 11:04:49
I have some places in my code where I want to assure that a division of 2 arbitrary floating point numbers (32 bit single precision) won't overflow. The target/compiler does not guarantee (explicitly enough) nice handling of -INF/INF and (does not fully guarantees IEEE 754 for the exceptional values - (possibly undefined) - and target might change). Also I cannot make save assumtions on the inputs for this few special places and I am bound to C90 standard libraries. I have read What Every Computer Scientist Should Know About Floating-Point Arithmetic but to be honest, I am a little bit lost.

How to handle the divide by zero exception in List Comprehensions while dividing 2 lists in Python

由 ♀尐吖头ヾ 提交于 2019-12-06 02:39:10
问题 How to handle the divide by zero exception in List Comprehensions while dividing 2 lists in Python: From below example: from operator import truediv result_list = map(truediv, [i for i in list1], [j for j in list2]) where the list2 can contain the 0 as value. I want to handle the exception in the same line due to my code constrain. Please help me. 回答1: You cannot . try is a (compound) statement, a list-comprehension is an expression. In Python these are completely distinct things and you

How to prevent division by zero?

由 ▼魔方 西西 提交于 2019-12-06 01:06:23
问题 ads = ads.Where(x => (x.Amount - x.Price) / (x.Amount / 100) >= filter.Persent); if x.Amount == 0 I have error "Divide by zero error encountered." like me in this request is to avoid? update: this helped, but I do not like the decision: ads = ads.Where(x => (x.Amount - x.Price) / ((x.Amount / 100)==0?0.1:(x.Amount / 100)) >= filter.Persent); there is another way? 回答1: ads = ads.Where(x => x.Amount != 0 && (x.Amount - x.Price) / (x.Amount / 100) >= filter.Persent); 回答2: Of course, you can

Linear Programming - variable that equals the sign of an expression

由 血红的双手。 提交于 2019-12-05 18:28:10
I am trying to write a linear program and need a variable z that equals the sign of x-c, where x is another variable, and c is a constant. I considered z = (x-c)/|x-c| . Unfortunately, if x=c, then this creates division by 0. I cannot use z=x-c, because I don't want to weight it by the magnitude of the difference between x and c. Does anyone know of a good way to express z so that it is the sign of x-c? Thank you for any help and suggestions! You can't model z = sign(x-c) exactly with a linear program (because the constraints in an LP are restricted to linear combinations of variables).

Divide by zero error, how do I fix this?

由 安稳与你 提交于 2019-12-05 02:29:20
C# novice here, when the int 'max' below is 0 I get a divide by zero error, I can see why this happens but how should I handle this when max is 0? position is also an int. private void SetProgressBar(string text, int position, int max) { try { int percent = (100 * position) / max; //when max is 0 bug hits string txt = text + String.Format(". {0}%", percent); SetStatus(txt); } catch { } } Simon int percent = 0 if (max != 0) percent = (100*position) / max Well, that entirely depends on the behaviour you want. If the maximum value of your program bar is zero, is it full? Is it empty? This is a
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