floating-point

问题 I'm just trying to compute a good sigmoid function in C++ (and efficient). So i have to do something like: 1/(1 + exp(-x)) The problem is, when X becomes big (or even small), the result of 1 + e turns to be 0 or 1 For example, 1 + exp(-30) = 1 But this is incorrect... How can we add very small (or big) numbers easily and efficiently ? Datatype I am using : double Here is the code snippet : double Quaternion::sigmoidReal(double v){ return 1.0 / ( 1.0 + exp(-v) ) ; } Thanks ! 回答1: I think you

问题 I am trying to change the elements of a list of strings to floats using the method defined in this thread. I write with open('posx_mean_no_acoplo_tf_multiple.txt', 'r') as fmediaXoriginal: contentmediaXoriginal = fmediaXoriginal.readlines() contentmediaXoriginal = [x.strip() for x in contentmediaXoriginal] [float(i) for i in contentmediaXoriginal] As specified in the other thread. However, if I write print(type(contentmediaXoriginal[2])) , then, the output is <class 'str'> . As far as I can

问题 I am trying to change the elements of a list of strings to floats using the method defined in this thread. I write with open('posx_mean_no_acoplo_tf_multiple.txt', 'r') as fmediaXoriginal: contentmediaXoriginal = fmediaXoriginal.readlines() contentmediaXoriginal = [x.strip() for x in contentmediaXoriginal] [float(i) for i in contentmediaXoriginal] As specified in the other thread. However, if I write print(type(contentmediaXoriginal[2])) , then, the output is <class 'str'> . As far as I can

问题 So I'm coding a little bot in python and I'm having a problem. It seems to be a common problem, but I've never seen it asked in the same situation I'm in. Ok so here is the code posing problem : old_values = float((removeprc(browser.find_element_by_xpath('//*[@id="draggableNavRightResizable"]/section/section[2]/section[1]/div[3]/ul/li[1]/div[2]/div[6]/span').text))) browser.find_element_by_xpath('//*[@id="draggableNavRightResizable"]/section/section[2]/section[1]/div[3]/ul/li[1]/div[2]/div[6]

问题 I am creating a bot that would automate my work and copy particular values from a particular website. Everything works fine but the last lines of my code that says w.text produces an outcome which is text and I need a number. Each element that I need the value of looks like this after inspection: <span class="good">€25,217.65</span> How do I get the value as a number instead of as a text? I tried w.value or w.get_attribute('value) but it doesn't work. Here is my program (excluding downloads

问题 Suppose I could look at a float as if it was some sort of a dict, in which the the keys range from -infinity to infinity, and the values are the digits in these places. That is, f[i] will return the integer which is closest to (f % 10**(i+1) - f % 10**i) / 10**i . For example, if f=1234.5678 , f[-1] == 5 and f[2] == 2 . Furthermore: imagine the float would also support some weird form of image slicing (even though it is not a list, just like it is not a dict), so in our example f[-1:2] == 345

问题 I need to link my firmware (running on STM32L4x6, built with arm-none-eabi_gcc) with two third party libraries (I don't have the source code of these libs). One lib is compiled using hard float abi, and the other is not using float at all and linked probably with soft float abi. I know both abis are not compatible and I fully understand the difference between them, but what if a library does not use float operation at all ? What is preventing to link it with some other code using whatever abi

问题 I need to link my firmware (running on STM32L4x6, built with arm-none-eabi_gcc) with two third party libraries (I don't have the source code of these libs). One lib is compiled using hard float abi, and the other is not using float at all and linked probably with soft float abi. I know both abis are not compatible and I fully understand the difference between them, but what if a library does not use float operation at all ? What is preventing to link it with some other code using whatever abi

问题 I need to link my firmware (running on STM32L4x6, built with arm-none-eabi_gcc) with two third party libraries (I don't have the source code of these libs). One lib is compiled using hard float abi, and the other is not using float at all and linked probably with soft float abi. I know both abis are not compatible and I fully understand the difference between them, but what if a library does not use float operation at all ? What is preventing to link it with some other code using whatever abi

问题 I need to link my firmware (running on STM32L4x6, built with arm-none-eabi_gcc) with two third party libraries (I don't have the source code of these libs). One lib is compiled using hard float abi, and the other is not using float at all and linked probably with soft float abi. I know both abis are not compatible and I fully understand the difference between them, but what if a library does not use float operation at all ? What is preventing to link it with some other code using whatever abi